AT-rich interactive domain-containing protein 1A, also known as p270, is a protein that in humans is encoded by the ARID1A gene. This gene encodes a member of the SWI/SNF families, whose members have helicase and ATPase activities and are thought to regulate transcription of certain genes by altering the chromatin structure around those genes. ARID1A is mapped to 1p36.11. It possesses at least two conserved domains that could be important for its function. First, it has a DNA-binding domain that can specifically bind an AT-rich DNA sequence known to be recognized by a SNF/SWI complex at the beta-globin locus. Second, the C-terminus of the protein can stimulate glucocorticoid receptor-dependent transcriptional activation.