Cathepsin B

Cathepsin B is in humans encoded by the CTSB gene. Cathepsin B belongs to a family of lysosomal cysteine proteases and plays an important role in intracellular proteolysis. Upregulation of cathepsin B is found in premalignant lesions and various pathological conditions, as well as cancers. CTSB gene is located at chromosome 8p22, consisting of 13 exons.The promoter of CTSB gene contains a GC-rich region including many SP1 sites, which is similar to housekeeping gene. At least five transcript variants encoding the same protein have been found for this gene.