Impaired CatB synthesis and activity were shown to be involved in the pathogenesis of multiple diseases (Fig. 7), such as rheumatoid arthritis [41, 42], liver fibrosis [43], traumatic brain injury [44], hypoxia-ischemic brain injury [45], inflammatory pain [46], pancreatitis [47], Alzheimer’s disease [48–50], cancer [51, 52], and COVID-19 infection [53, 54]. Here, TYRP1 is linked to early-onset autosomal dominant Alzheimer disease.