Alternatively, ABPs and qABPs have been developed for detecting cathepsin activities from a diverse range of pathological conditions, such as osteoarthritis (cathepsins B, L and S [56]), inflammation (cathepsin S [57]), idiopathic pulmonary fibrosis (cysteine cathepsins [58]), Atherosclerosis [59], breast cancer (cathepsins X, B, S and L [60]) and lung cancer [61]. Here, CTSS is linked to idiopathic pulmonary fibrosis.