biostudies-literatureLu MYNHGRI NIH HHSNIGMS NIH HHS466-473https://www.ebi.ac.uk/biostudies/studies/S-EPMC11464372biostudies-literatureUnknown634(8033)Computational pathology^1,2 has witnessed considerable progress in the development of both task-specific predictive models and task-agnostic self-supervised vision encoders^3,4. However, despite the explosive growth of generative artificial intelligence (AI), there have been few studies on building general-purpose multimodal AI assistants and copilots⁵ tailored to pathology. Here we present PathChat, a vision-language generalist AI assistant for human pathology. We built PathChat by adapting a foundational vision encoder for pathology, combining it with a pretrained large language model and fine-tuning the whole system on over 456,000 diverse visual-language instructions consisting of 999,202 question and answer turns. We compare PathChat with several multimoNatureA multimodal generative AI copilot for human pathology.PMC11464372R35 GM149270T32 HG002295Patel AKim ALu MYGerber GPouli DSoliman AChen CWeishaupt LLChen BMahmood FChen RJChow AKZhao MWilliamson DFKDing TLiang ILe LPIkemura KWang JJParwani AVfalseA multimodal generative AI copilot for human pathology.Computational pathology^1,2 has witnessed considerable progress in the development of both task-specific predictive models and task-agnostic self-supervised vision encoders^3,4. However, despite the explosive growth of generative artificial intelligence (AI), there have been few studies on building general-purpose multimodal AI assistants and copilots⁵ tailored to pathology. Here we present PathChat, a vision-language generalist AI assistant for human pathology. We built PathChat by adapting a foundational vision encoder for pathology, combining it with a pretrained large language model and fine-tuning the whole system on over 456,000 diverse visual-language instructions consisting of 999,202 question and answer turns. We compare PathChat with several multimo2024-01-01T00:00:00Z2024 Oct2026-07-14T20:37:28.879Z2025-04-06T03:48:06.068ZS-EPMC114643723886605010.1038/s41586-024-07618-3