# 🔬Causal Models Need Causal Data - Xaira’s X-Cell model for Drug Discovery (Bo Wang & Ci Chu, Chief Discovery Officer & Chief AI Scientist) Page: https://stenobird.com/podcast/latent-space-ai-engineer/causal-models-need-causal-data-xaira-s-x-cell-model-for-drug-discovery-bo-wang-ci-chu-chief-discovery-officer-chief-ai-scientist Text version: https://stenobird.com/podcast/latent-space-ai-engineer/causal-models-need-causal-data-xaira-s-x-cell-model-for-drug-discovery-bo-wang-ci-chu-chief-discovery-officer-chief-ai-scientist.md Podcast: [Latent Space: The AI Engineer Podcast](https://stenobird.com/podcast/latent-space-ai-engineer) Published: 2026-07-21T19:34:06+00:00 Episode link: https://www.latent.space/p/xaira Audio file: https://api.substack.com/feed/podcast/207941607/06ca3e4bd112d187109d3b25b2c9d8fc.mp3 Processing state: processed JSON: https://stenobird.com/v1/public/podcasts/latent-space-ai-engineer/episodes/causal-models-need-causal-data-xaira-s-x-cell-model-for-drug-discovery-bo-wang-ci-chu-chief-discovery-officer-chief-ai-scientist Duration seconds: 5387 ## Resource Scaling AI for drug discovery requires moving beyond parameter count to information-rich causal data. Xaira Therapeutics' X-Cell model demonstrates that integrating high-throughput perturbation data allows models to predict how unseen cell lines respond to interventions. ## Highlights - Main idea: Scaling laws for biological models are limited by data information content, not just compute or parameters - Technical shift: Moving from auto-regressive models (like scGPT) to diffusion-based architectures allows for better modeling of high-dimensional gene expression as an 'editing' process - Practical takeaway: High-throughput experimentation is essential to generate the causal datasets needed to predict gene expression changes after perturbations - Failure mode: Training on static datasets like CELLxGENE can capture cell states but fails to predict the dynamics of cellular interventions - Future frontier: The next breakthrough in 'virtual cell' modeling depends on longitudinal sequencing technology that can track the same cell over multiple time points ## Topics Drug Discovery, Diffusion Language Models, Gene Expression, Single-cell RNA sequencing, Causal Inference, Bioinformatics, Xaira Therapeutics, Virtual Cell Models ## Chapters - 1:00 — Introduction to Xaira Therapeutics: An introduction to Bo Wang and Ci Chu and their mission to build an AI-driven drug discovery platform. - 8:00 — The Power of Predictive Models: Discussing the 'wow moment' when models successfully predict responses to unseen cell line perturbations. - 15:00 — The Shift to Data-Driven Interventions: Exploring how the rise of LLMs has influenced the approach to modeling biological interventions. - 21:00 — The Necessity of Causal Data: Why large-scale datasets like CELLxGENE are foundational but require causal context for true predictive power. - 28:00 — Scaling Perturbation Response: The challenges and opportunities in using high-throughput techniques to scale biological data collection. - 42:00 — Diffusion vs. Auto-regressive Models: A technical deep dive into why diffusion models are superior for modeling gene expression as an iterative refinement process. - 55:00 — Validating New Biology: Discussing the recent results from the X-Cell preprint and the discovery of new biological insights. ## Actions - request_transcript: `POST https://stenobird.com/v1/public/podcasts/latent-space-ai-engineer/episodes/causal-models-need-causal-data-xaira-s-x-cell-model-for-drug-discovery-bo-wang-ci-chu-chief-discovery-officer-chief-ai-scientist/transcription-requests` — Idempotently request low-priority transcript generation for this episode. - read_markdown: `GET https://stenobird.com/podcast/latent-space-ai-engineer/causal-models-need-causal-data-xaira-s-x-cell-model-for-drug-discovery-bo-wang-ci-chu-chief-discovery-officer-chief-ai-scientist.md` — Read the agent-friendly Markdown representation of this episode resource. A page view does not enqueue transcription. Agents should invoke `request_transcript` explicitly when they need this episode processed. ## Transcript Full transcripts are not published on public pages unless there is a clear rights basis.