AT-rich interactive domain-containing protein 1B is a protein that in humans is encoded by the ARID1B gene. ARID1B is a component of the human SWI/SNF chromatin remodeling complex.

Germline mutations in ARID1B are associated with Coffin–Siris syndrome. Somatic mutations in ARID1B are associated with several cancer subtypes, suggesting that it is a tumor suppressor gene.

ARID1B has been shown to interact with SMARCA4 and SMARCA2.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.