Cystatin F (leukocystatin) is a human gene encoded by the symbol, CST7. It may also be known as: Cystatin-F; Cystatin-7; Cystatin-like metastasis-associated protein; CMAP; Leukocystatin; cystatin F (leukocystatin). The encoded protein has an amino acid length of 145 and a mass of 16.5 kDa. Other isoforms may exist. Homologs of this gene exist in other organisms, including: Rat, Frog.