Placenta-specific 1, or, PLAC1, is a human gene. Other names include: Placenta-specific protein 1; cancer/testis antigen 92; CT92; OOSP2L; placenta-specific 1. The encoded protein has an amino acid length of 212 and a mass of 23.6 kDa. Other isoforms may exist. Placenta-specific 1 is a member of the PLAC1 family. This gene shares homology with other species, including: Rat.