STAT3 and autoimmune disease: SARS-CoV-2 activated NF-κB and STAT3 through the AngI–AT1R pathway after SARS-CoV-2 infection, and then activated IL-6 amplifier (IL-6 Amp), which was a mechanism for STAT3 to overactivate NF-κB and led to various inflammations and autoimmune diseases (66).