BMSL, the Bayesian Multitask with Structure Learning model, is a repository that accompanies a paper: “Bayesian Multitask Learning Regression for Heterogeneous Patient Cohorts” from the Journal of Biomedical Informatics. Multitask learning (MTL) is a sub-field of machine learning in which individual models for performing potentially related tasks are learned jointly. The Bayesian MTL model infers the task relationship structure directly from the data.