Cytotoxicity against virus-infected alveolar epithelial cells by γδ T cells has been shown for influenza virus45 and might involve atypical pathways alternative to granzyme B and perforin, which are more commonly used by CD8+ T cells and natural killer cells and could be impaired in COVID-19 and MAS.1, 29, 31 Specifically, γδ T cells might exert cytotoxic effects through the TNF-related apoptosis-inducing ligand, Fas ligand, and granzyme K,39, 45 which are all overexpressed in the lungs of patients with COVID-19,11, 15 and might therefore explain how γδ T cells cause diffuse damage to the alveolar epithelium (figure 1).