CTSB and cancer: There are 12 membersof the caspase family, termed caspase-1 to caspase-12, and their nameis derived from their cysteine protease activity (i.e., a cysteineresidue in the active site cleaves target proteins, typically afteran aspartic acid residue).92 They haveessential functions in programmed cell death, also known as apoptosis,and their activity can be either tumor-suppressing or tumor-promotingdepending on the tissue microenvironment, making them interestingbiomarkers in cancer research.93