PR55A, or Protein phosphatase 2 regulatory subunit B, alpha, is a human gene encoded by PPP2R2A. It may also be known as: Serine/threonine-protein phosphatase 2A 55 kDa regulatory subunit B alpha isoform; PP2A subunit B isoform PR55-alpha; PP2A subunit B isoform R2-alpha; PP2A subunit B isoform alpha; PP2A subunit B isoform B55-alpha; B55A; B55ALPHA; PR52A; protein phosphatase 2, regulatory subunit B, alpha. The encoded protein has an amino acid length of 447 and a mass of 51.7 kDa. Other isoforms may exist. PR55A is a member of the Phosphatase 2A regulatory subunit B family. Homologs of this gene exist in other organisms, including: Mouse, Rat, Zebrafish, Frog, Chicken.