CTSS and cancer: Cathepsin Z (CTSZ), is a cathepsin family member and located in a frequently amplified region at 20q13.2.5 It contains an Arg‐Gly‐Asp (RGD) motif, which is cleaved and removed following its activation.6 RGD is a sequence that is important for the protein to bind cell surface and mediate cell migration and adhesion.7 Compared with other members of the cathepsin family, relatively little is known about the roles of CTSZ in cancer progression.