CES6, or Carboxylesterase 4A, is a human gene encoded by CES4A. It may also be known as: Carboxylesterase 4A ; CES8. The encoded protein is an enzyme with an amino acid length of 561 and a mass of 63.5 kDa. CES6 is a member of the Type-B carboxylesterase/lipase family. Homologs of this gene exist in other organisms, including: Mouse, Rat.