CD274 and COVID-19: A unique immunological profile was found in the peripheral blood of COVID-19 patients with an increased number of NK cells, but low T cell numbers and overexpression of T cell immunoglobulin and mucin domain (TIM)-3,  programmed cell death ligand 1 (PD-L1) and CD69 in both immune effector cells suggesting a hyperactivated and exhausted immune response upon COVID-1 infection [54].