Peptidylarginine deiminases (PADs) are a family of five enzymes that catalyze the conversion of arginine to citrulline in peptides and proteins. PAD2 is the most widely expressed and conserved member across mammalian species, implying it is the ancestral homologue of the PADs. Cayman's PAD2 (human) ELISA Kit is a sandwich assay that can be used to measure PAD2 in tissue culture medium, cell lysates, plasma, and serum.