STAT3 and cancer: Based on the above analysis, it may be concluded that the equilibrium and disequilibrium of all type 1 cellular immune responses can be attributed to “normal” and “abnormal” IFNγ/STAT1 and/or TGFβ/STAT3 signaling, such as the acute Fib-dominated immune imbalance caused by lethal Py infection, the possible acute Fib-dominated immune imbalance caused by SARS-CoV-2 infection, and the hyperprogression of disease in cancer immunotherapy may all be caused by the acute blockade of the IFNγ/STAT1 signaling, and/or the acute overactivity of TGFβ/STAT3 pathway.