{Reference Type}: Journal Article {Title}: Know your enemy and know yourself - the case of SARS-CoV-2 host factors. {Author}: Lee WS;Yousefi M;Yan B;Yong CL;Ooi YS; {Journal}: Curr Opin Virol {Volume}: 50 {Issue}: 0 {Year}: 10 2021 {Factor}: 7.121 {DOI}: 10.1016/j.coviro.2021.08.007 {Abstract}: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the etiologic agent that causes Coronavirus Disease 2019 (COVID-19) pandemic, is a newly emerging respiratory RNA virus with exceptional transmissibility and pathogenicity. Numerous COVID-19 related studies have been fast-tracked, with the ultimate goal to end the pandemic. Here we review the major stages of SARS-CoV-2 infection cycle in cells, with specific emphasis on essential host factors. Insights into the cell biology of SARS-CoV-2 infection have accelerated the development of host-directed therapeutics, as shown by dozens of clinical trials evaluating COVID-19 treatments using host-targeting compounds.