SELL and COVID-19: Flow cytometry analysis by manual gating further revealed increased expression of perforin, Ksp37, MIP-1β (macrophage inflammatory protein-1β), CD98, Tim-3, and granzyme B in CD56bright NK cells from COVID-19 patients, as well as CD98, Tim-3, NKG2C, MIP-1β, and CD62L, among other markers, in CD56dim NK cells (Fig. 2, C and D, and fig.