Sukhova et al. (2003) demonstrated that cathepsin S (CTSS) deficiency can slow the progression of atherosclerosis in a low-density lipoprotein (LDL) receptor-deficiency-induced atherosclerosis mouse model. Other members of the CTS family (e.g., CTSL and CTSK) have been shown to be involved in the process of atherosclerosis by mediating inflammation and regulating the immunity response (Lutgens et al., 2006; Kitamoto et al., 2007). Here, CTSL is linked to atherosclerosis.