Protein phosphatase 2A (PP2A) is a major intracellular protein phosphatase that regulates multiple aspects of cell growth and metabolism. The ability of this widely distributed heterotrimeric enzyme to act on a diverse array of substrates is largely controlled by the nature of its regulatory B subunit. There are multiple families of B subunits (See also Pfam:PF01240), this family is called the B56 family [1].

1: Identification of a new family of protein phosphatase 2A regulatory subunits. McCright B, Virshup DM; J Biol Chem 1995;270:26123-26128. PMID:7592815