KLRC2 and COVID-19: Therefore, the impaired ADCC response observed in patients with critical COVID-19 may account for CMV and EBV reactivation despite that activating receptors such as NKp44 and NKp46, involved in the killing of HSV-1-infected cells (66), and NKG2C, involved in the generation of CMV induced adaptive responses (67, 68), are generally overexpressed in these individuals (7).