“…Interestingly, TMPRSS2 and TMPRSS4 had been previously ascribed diverse roles in mucosal pathobiology, including that of the lung, such as the activation of influenza and SARS-CoV viruses [ 39 , 40 , 41 ], promotion of lung fibrosis [ 42 ], as well as the induction of lung cancer stem-cell-like properties [ 43 ], growth, metastasis, and resistance to chemotherapy [ 44 ]. It is worthwhile to mention that patients with cancer, including lung malignancy, were shown to represent a population that is extremely vulnerable to COVID-19 [ 3 , 45 ]. It is plausible to surmise that a better understanding of the expression of SARS-CoV-2 receptors is highly warranted in lung cancer patients, particularly in LUADs, whose pathogenesis is linked to ACE2 -expressing airway lineages (e.g., AT2), and also since LUADs arise in the lung periphery, a major site for the development of pneumonia in COVID-19 patients.…”