– Mouse Cystatin F belongs to cystatin superfamily, which encompasses proteins that contain multiple cystatin-like sequences. It has been shown that Cystatin F is selectively expressed by hematopoietic cells and may be a biomarker for both liver metastasis and inflammatory lung disorders. Mouse Cystatin F inhibits papain and cathepsin L but with affinities lower than other cystatins. It may play a role in immune regulation through inhibition of a unique target in the hematopoietic system.