Phosphatase 2A affects a variety of biological processes in the cell such as transcription, cell cycle progression and cellular morphogenesis, and provides an initial identification of critical substrates for this phosphatase. The regulatory subunit may direct the catalytic subunit to distinct, albeit overlapping, subsets of substrates (By similarity). PP2A exists in several trimeric forms, all of which consist of a core composed of a catalytic subunit associated with a 65 kDa (PR65) (Subunit A) and a 55 kDa (PR55) (Subunit B) regulatory subunit. Belongs to the phosphatase 2A regulatory subunit B family.