Anti-Peptide YY antibodies are used in the immunodetection of the protein encoded by the PYY gene. In humans, the canonical protein has a reported length of 97 amino acid residues and a mass of 11.1 kDa. It is known to be a secreted protein. Alternative splicing is reported to yield 2 different isoforms for this protein. A member of the NPY protein family, it is known to be involved with intestinal epithelial cell differentiation. Post-translational modifications have been described, including protein cleavage. Other names for this target antigen include PYY1, peptide tyrosine tyrosine, prepro-PYY, and PYY-I.