This gene encodes a regulatory subunit of the serine/threonine phosphatase, protein phosphatase 2. This protein is localized to both nuclear and cytoplasmic regions depending on cell cycle phase. Homozygous conditional knockout mice for this gene exhibit reduced numbers and impaired proliferation of immune system B cells. This protein may regulate the expression of the P-glycoprotein ATP-binding cassette transporter through its phosphatase activity. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2015].