Main molecules intersecting COVID-19 and cancer included tumor necrosis factor α (TNF-α) (Balkwill, 2009; Huang et al., 2020), exportin 1 (XPO1) (Uddin et al., 2020; Azmi et al., 2021), Bruton tyrosine kinase (BTK) (Byrd et al., 2016; Roschewski et al., 2020), TMPRSS2 (Lin et al., 1999; Hoffmann et al., 2020; Raghav et al., 2020), NKG2A (André et al., 2018; Antonioli et al., 2020), and C5aR (Wang et al., 2019; Woodruff and Shukla, 2020). This evidence concerns the gene BTK and COVID-19.