SCCA-1 is an alias for the gene, Serpin peptidase inhibitor, clade B (ovalbumin), member 4, in humans. Other names include: Serpin B4; Peptidase inhibitor 11; PI-11; Squamous cell carcinoma antigen 2; SCCA-2; Leupin; PI11; SCCA1. The encoded protein has an amino acid length of 390 and a mass of 44.9 kDa. SCCA-1 is a member of the Serpin family, Ov-serpin subfamily. This gene shares homology with other species, including: Mouse.