To assess MFQ-NP efficacy against the COVID-19 pandemic virus, SARS-CoV-2, we used two different cell lines: Vero E6 cells that do not express human TMPRSS2, therefore favoring SARS-CoV-2 infection by endocytosis; and Calu-3 human alveolar epithelial adenocarcinoma cells with a high expression of TMPRSS2, thus favoring SARS-CoV-2 spike cleavage and fusion at the plasma membrane. The gene discussed is TMPRSS2; the disease is COVID-19.