Biological AI models increasingly predict complex cellular responses, yet their learned representations remain disconnected from the molecular processes they aim to capture. We present CDT-III, which extends mechanism-oriented AI across the full central dogma: DNA, RNA, and protein. Its two-stage Virtual Cell Embedder architecture mirrors the spatial compartmentalization of the cell: VCE-N models transcription in the nucleus and VCE-C models translation in the cytosol. On five held-out genes, CDT-III achieves per-gene RNA r=0.843 and protein r=0.969. Adding protein prediction improves RNA performance (r=0.804 to 0.843), demonstrating that downstream tasks regularize upstream representations. Protein supervision sharpens DNA-level interpretability, increasing CTCF enrichment by 30%. Analysis of experimentally measured mRNA and protein responses reveals that the majority of genes with observable mRNA changes show opposite protein-level changes (66.7% at |log2FC|>0.01, rising to 87.5% at |log2FC|>0.02), exposing a fundamental limitation of RNA-only perturbation models. Despite this pervasive direction discordance, CDT-III correctly predicts both mRNA and protein responses. Applied to in silico CD52 knockdown approximating Alemtuzumab, the model predicts 29/29 protein changes correctly and rediscovers 5 of 7 known clinical side effects without clinical data. Gradient-based side effect profiling requires only unperturbed baseline data (r=0.939), enabling screening of all 2,361 genes without new experiments.
Figures & tables
Figure 1: CDT-III two-stage Virtual Cell Embedder architecture. VCE-N (nuclear stage, identical to CDT-II) processes DNA Enformer embeddings and per-cell RNA expression through self-attention and cross-attention, modeling transcription to produce a cell-level RNA embedding. VCE-C (cytosolic stage) takes this RNA embedding and protein expression, modeling translation to produce a protein embedding. Each stage has an independent task head.
Gene
Cells
RNA r (CDT-II)
RNA r (CDT-III)
Δ
Protein r (expr.)
GFI1B
477
0.851
0.885
+0.034
0.969
TNFSF9
349
0.831
0.868
+0.037
0.991
TFRC
847
0.824
0.854
+0.030
0.989
CD44
233
0.795
0.858
+0.063
0.935
CD52
131
0.719
0.748
+0.029
0.962
Mean
0.804
0.843
+0.039
0.969
Table 1: Per-gene prediction performance. Per-gene mean r (pseudo-bulk) on five held-out validation genes. CDT-II values are from the same checkpoint used for CDT-III weight transfer. RNA per-gene mean r improves from CDT-II ( 0.804 ) to CDT-III ( 0.843 ) despite adding a second task. Protein per-gene mean r on 65 expressed proteins reaches 0.969 .
Figure 2: Prediction performance. (A) Single-stage vs. two-stage VCE comparison (RNA r by architecture). (B) Per-gene RNA correlation: CDT-II vs. CDT-III. (C) Per-gene protein predicted vs. actual (65 expressed proteins, 5 genes).
Metric
CDT-II
CDT-III
Change
Mean CTCF enrichment
6.6×
8.59×
+30%
Genes >2× enriched
—
27/27 (100%) †
—
Permutation P
<0.001
<0.001
—
Hi-C mean contact ratio
—
1.30×
—
Genes with ratio >1
—
16/25 (64%)
—
Wilcoxon P
—
0.020
—
Table 2: CTCF enrichment and Hi-C validation. Protein supervision improves DNA-level interpretability.
Figure 3: Protein supervision improves DNA interpretability. (A) Hi-C contact ratio per gene (top 20 attention bins vs. random 20 bins; mean =1.30× , P=0.020 ). (B) Attention-high vs. random bins scatter plot showing that high-attention genomic regions have stronger physical contact with promoters.
Known side effect
Incidence
CDT-III predicted proteins
Match
Autoimmune thyroid disease
36–42%
FCGR2A ↑ , BAFF-R ↑ , CD40 ↑
✓
ITP
2–3%
FCGR2A ↑
✓
Infection risk
66–77%
CD58 ↑⋆ , TFRC ↑⋆
✓
Infusion reaction
> 90%
ICAM1 ↑ , CD29 ↑
✓
Autoimmune nephropathy
0.2–0.3%
MCAM ↑
✓
Goodpasture syndrome
< 0.1%
—
✗
Table 3: CDT-III predictions vs. known Alemtuzumab side effects. Five of seven known side effects are recapitulated by CDT-III’s protein predictions, without access to any clinical data.
Figure 4: In silico Alemtuzumab side effect prediction. (A) CD52 knockdown RNA prediction vs. actual (per-gene r=0.748 ). (B) Protein prediction vs. actual for 65 expressed proteins ( r=0.962 ). (C) Side effect map: predicted vs. measured protein changes for 29 proteins with detectable effects (29/29 direction agreement, color-coded by clinical relevance).
Appendix figures & tables12 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 5: CDT-II architecture. The model mirrors the central dogma: DNA self-attention captures genomic relationships within a ± 57 kb window, RNA self-attention captures gene co-regulation, and cross-attention models transcriptional control. A Virtual Cell Embedder integrates both modalities to predict perturbation effects. CDT-III’s VCE-N preserves this architecture exactly, enabling 100% weight transfer.
Architecture
λ
RNA r
Protein r
Fusion transfer
CDT-II
RNA only
—
0.64
—
—
Exp A
1-Stage
1.0
0.19
0.76 ∗
✗
Exp B
1-Stage
0.11
0.24
0.77 ∗
✗
Exp C
1-Stage
0.05
0.35
0.81 ∗
✗
Exp D
1-Stage
0.01
0.37
0.80 ∗
✗
Exp E
1-Stage ( λ warmup)
0.001 → 0.01
0.30
0.21
✗
Appendix
Table 4: Single-stage vs. two-stage VCE. Per-cell correlation ( r ) on the validation set. All models transfer CDT-II encoder and attention weights; the critical difference is the VCE fusion layer. Single-stage architectures modify fusion dimensions ( d×2→d×3 ), preventing fusion weight transfer and causing RNA prediction to collapse despite encoder transfer. The two-stage architecture preserves full weight compatibility including fusion. ∗ Protein r values for single-stage models are inflated by 124/189 non-expressed proteins predicted as ∼ 0.
Attention Map
Shape
Biological Meaning
Source
DNA Self-Attention (L0)
[8,896,896]
Genomic interactions
CDT-II
DNA Self-Attention (L1)
[8,896,896]
Higher-order genomic
CDT-II
RNA Self-Attention
[8,2361,2361]
Gene co-regulation
CDT-II
DNA → RNA Cross-Attention
[8,2361,896]
Transcriptional control
CDT-II
Protein Self-Attention
[8,189,189]
Protein co-regulation
CDT-III
RNA → Protein Cross-Attention
[8,189,2361]
Translational control
CDT-III
Appendix
Table 5: Attention map inventory. CDT-III produces six interpretable attention maps, each corresponding to a specific biological process. Four are inherited from CDT-II; two are new.
Gene
CTCF
Top 10%
Enrich.
Gene
CTCF
Top 10%
Enrich.
CD82
7
7
10.0 ×
SLC3A2
6
5
8.33 ×
CD69
7
7
10.0 ×
TNFSF9
5
4
8.00 ×
CD40
9
9
10.0 ×
CD44
4
3
7.50 ×
ITGB1
2
2
10.0 ×
CD58
4
3
7.50 ×
ENTPD1
2
2
10.0 ×
CD55
4
3
7.50 ×
KLRG1
3
3
10.0 ×
LGALS3
4
3
7.50 ×
Appendix
Table 6: CTCF enrichment for all 28 genes with ENCODE K562 ChIP-seq data. 14/27 genes with CTCF sites show perfect 10.0 × enrichment (all CTCF sites in top 10% attention bins).
Exp
λ
Strategy
RNA r
Prot r
Epochs
Notes
A
1.0
Fixed
0.19
0.76
148
Protein-dominated loss
B
0.11
Fixed
0.24
0.77
209
Equal-weight by variance
C
0.05
Fixed
0.35
0.81
386
Best single-stage protein
D
0.01
Fixed
0.37
0.80
472
Best single-stage RNA
E
0.001 → 0.01
Warmup
0.30
0.21
∼ 300
Curriculum failed
Appendix
Table 7: Full results for all five single-stage VCE experiments.
Rank
Protein (Gene)
Gradient
Category
1
CD32 (FCGR2A)
+0.059↑
Fc receptor / ADCC
2
CD146 (MCAM)
+0.044↑
Endothelial adhesion
3
CD54 (ICAM1)
+0.043↑
Inflammatory adhesion
4
CD81 (CD81)
+0.031↑
B cell co-receptor
5
CD58 (CD58)
+0.030↑
T cell activation (LFA-3)
6
CD224 (GGT1)
+0.030↑
Oxidative stress
Appendix
Table 8: Top 20 proteins predicted to change upon CD52 knockdown (gradient-based analysis).
Gene
Top 20 Hi-C
Random 20 Hi-C
Ratio
Note
CD55
156.4
56.8
2.75×
Complement regulator
CD82
66.2
29.0
2.28×
Tetraspanin
IL21R
68.6
31.2
2.20×
IL-21 receptor
FCGR2A
93.8
45.1
2.08×
Fc receptor
CD83
71.5
36.0
1.99×
Dendritic cell
ITGB1
51.3
29.9
1.72×
Integrin β 1
Appendix
Table 9: Per-gene Hi-C contact ratios for all 25 genes with sufficient coverage (4DN K562 data, 5 kb resolution). Three genes excluded due to zero Hi-C records: B2M , TFRC , GFI1B . Mean ratio =1.30× ; 16/25 genes show ratio >1 ( P=0.020 , Wilcoxon signed-rank).
Metric
All proteins (189)
Expressed proteins (65)
Pearson r
0.913
0.939
Spearman ρ
0.752
0.865
Direction agreement
145/189 (76.7%)
63/65 (96.9%)
Top 20 direction agreement
20/20 (100%)
—
Appendix
Table 10: Gradient analysis validation: NTC mean vs. perturbation cell input. Concordance between protein-level gradients ( ∂y^Prot,j/∂xRNA, CD52 ) computed using NTC mean input (no perturbation data) vs. actual CD52-perturbed cell input.
∣log2FC∣ threshold
N genes
Opposite
Same
% Opposite
>0 (all nonzero)
26
16
10
61.5%
>0.005
16
10
6
62.5%
>0.01
12
8
4
66.7%
>0.02
8
7
1
87.5%
>0.05
4
4
0
100.0%
Appendix
Table 11: Sensitivity analysis of mRNA–protein direction divergence. For each mRNA change threshold, we report the number of gene–protein pairs with opposite vs. same direction of change following CD52 knockdown. mRNA: full transcriptome log2FC; protein: DSB-normalized effects (65 expressed proteins, 27 matched pairs).
Figure 6: mRNA vs. surface protein response divergence after CD52 knockdown. Left: Paired bar chart for 12 genes with ∣mRNA log2FC∣>0.01 (DSB-normalized protein), showing mRNA change (blue) and protein change (red, scaled) for each gene. Dark colors indicate opposite-direction pairs (8/12, 66.7%); light colors indicate same-direction pairs. The dominant pattern—mRNA decreases while surface protein increases—is consistent with post-translational regulation. Right: Sensitivity analysis showing the percentage of gene–protein pairs with opposite directions at increasing mRNA change thresholds. The divergence rate rises from 61.5% to 100% as the threshold increases, indicating that genes with the strongest mRNA responses show the most pronounced protein-level discordance.
Figure 7: CD55 cross-attention genome track. DNA → RNA cross-attention profile (top) aligned with CTCF ChIP-seq peaks (bottom) across the ± 57 kb Enformer window. Red lines: CTCF sites in top 10% attention (3/4). TSS indicated by dotted line. Hi-C contact ratio: 2.75× (Table 9 ).
Figure 8: FCGR2A cross-attention genome track. Same format as Figure 7 . CTCF site in top 10% attention (1/2) located upstream of TSS, consistent with distal regulatory contact. Hi-C contact ratio: 2.08× .