In addition, cathepsin B has been involved in the progression of diseases like rheumatoid arthritis, liver fibrosis, neurological diseases, inflammatory pain, pancreatitis, hepatitis, myocarditis, cancer, and COVID-19 infection [5,6,7,8,9,10,11,12,13,28,29,30,37,38,39,40,41,42,43,44,45,46]. Here, CTSB is linked to rheumatoid arthritis.