Provided below are ELISA kits targeting phosphatidylinositol glycan anchor biosynthesis class U, a human protein encoded by PIGU. This protein is 435 amino acids long, with a mass of 50.1 kDa, and is a member of the PIGU family. 2 isoforms have been identified. Other alias names for this protein include: phosphatidylinositol glycan anchor biosynthesis class U protein, CDC91 (cell division cycle 91 S. cerevisiae homolog)-like 1, GPI transamidase component PIG-U, cell division cycle 91-like 1 protein, protein CDC91-like 1, and CDC91L1.