Protein phosphatase 2A (PP2A) is a hetertrimeric enzyme consisting of a catalytic subunits (C), a structural subunit (A) and a variable regulatory subunit (B). The B subunit family is made up of the , and isoforms. The PP2A/B isoform appears to only be detectable in the brain where it has been speculated that it cytoskeletal substrates. The RNA which produces the PP2A/B is developmentally regulated and increases sharply after birth. It has also been suggested that it may be important in the establishment and maintenance of neuronal connections. Synonyms: Protein Phosphatase 2 A/B 2.