The cysteine proteases, the papain-like proteases (PLpro) and 3-chymotrypsin-like protease (3CLpro) are essential for viral replication as they auto-proteolytically cleave the newly generated viral polyproteins chain to release the NSPs,5 which are pivotal to viral replication and, hence, more infections.6–8 Thus, they are attractive drug target for developing anti-SARS-CoV-2 drugs in COVID-19. This evidence concerns the gene CTSB and COVID-19.