GZMB and COVID-19: In acute COVID-19, SARS-CoV-2-specific CD8+ T cells exhibit high levels of IFN-γ, granzyme B, perforin, and CD107a molecules, some of which are present in the cytotoxic granules and are associated with potent cytotoxic effector functions (68, 124, 126, 145), developing fast CD8+ T cell responses (124).