Anti-HA3I antibodies enable researchers to detect and measure the HA3I antigen in biological samples. This target is a reported synonym of the KRT33A gene, which encodes keratin 33A. This protein is known to function in epithelial cell differentiation, among other biological roles. The human version of HA3I has a canonical amino acid length of 404 residues and a protein mass of 45.9 kilodaltons. It is reported to be notably expressed in the hair. This target antigen may also be known as Ha-3I.