Mediator complex subunit 12 is a gatekeeper of SARS-CoV-2 infection in breast cancer cells

Cancer patients are at increased risk for severe acute res-piratory syndrome coronavirus 2(SARS-CoV-2)infection and mortality.Like other viruses in the SARS family,SARS-CoV-2 employs two host proteins,angiotensin-converting enzyme 2(ACE2)and transmembrane serine protease 2(TMPRSS2),for viral entry.1 Recent studies showed that many of the host proteins identified as potential targets for developing COVID therapies are dysregulated in cancer,2 prompting us to investigate whether human cancer cells are susceptible to SARS-CoV-2 infection,and whether chemotherapy could modulate a cancer patient's risk for infection.