Here we used the weighted gene coexpression network analysis (WGCNA)8 platform to identify genes connected to two important components of COVID-19 biology: ACE2, which encodes the putative SARS-CoV-2 receptor3,4; and TMPRSS2, which encodes a protease that primes the SARS-CoV-2 spike protein and facilitates entry of the virus into cells3,10. Here, TMPRSS2 is linked to COVID-19.