Importantly, cell entry of the Omicron variant was not affected upon inhibition of Transmembrane Serine Protease 2 (TMPRSS2), as much as in the case of the WT or the Omicron Revertant variants [25], suggesting an altered mechanism of internalization utilized by the Omicron variant that likely serves as a basis for its enhanced infection of host cells. The gene discussed is TMPRSS2; the disease is infection.