NFKB1 and COVID-19: Several recent studies have demonstrated that SARS-CoV-2-PLpro is a multifunctional enzyme with deubiquitination and de-ISG activities via regulating multiple signalling pathways, such as STING, NF-κB, and TGF-β, to block immune responses (126), suggesting that PLpro can serve as an important therapeutic target against COVID-19.