STAT3 and cancer: In the light of the growing evidence that cancer patients might not respond adequately to COVID-19 vaccination [56,57,58,59,60], together with the recent discovery that a STAT3-related immune and proliferation transcriptional network is activated in COVID-19 cancer patients [61], it is important to broaden knowledge of the clinico-molecular interactions between SARS-CoV-2 and cancer at the level of STAT3.