PR65A, or Protein phosphatase 2 regulatory subunit A, alpha, is a human gene encoded by PPP2R1A. It may also be known as: Serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform; PP2A subunit A isoform PR65-alpha; PP2A subunit A isoform R1-alpha; Medium tumor antigen-associated 61 kDa protein; protein phosphatase 2A, regulatory subunit A, alpha isoform; protein phosphatase 2, 65kDa regulatory subunit A; PP2A-Aalpha; PP2AAALPHA; protein phosphatase 2, regulatory subunit A, alpha. The encoded protein has an amino acid length of 589 and a mass of 65.3 kDa. Other isoforms may exist. PR65A is a member of the Phosphatase 2A regulatory subunit A family. Homologs of this gene exist in other organisms, including: Mouse, Rat, Zebrafish, Frog.