Altered cathepsin activity has been associated with muscle wasting and inflammation, both key components of sarcopenia.[10] For instance, increased expression and activity of calpain and cathepsin B, L, and H in muscle tissues of patients with polymyositis or dermatomyositis suggest that these proteases play a pivotal role in the degradation of muscle fibers in inflammatory myopathies.[11]. The gene discussed is CTSB; the disease is sarcopenia.