ProGen2

ProGen2 is Salesforce Research's family of autoregressive protein language models, first released in 2022 and published in Cell Systems in 2023. The family spans 151M to 6.4B parameters, trained on natural proteins from UniRef90, the BFD metagenomic set, and antibody sequences.

Trained with next-residue prediction, the models can sample novel protein sequences from a prompt and score existing sequences as a zero-shot proxy for fitness. Checkpoints are BSD-3-Clause, free for academic and commercial use. Release timing below is era-level; the paper is the canonical reference.