In contrast, negative correlations observed between CD2 and IFN-γ, and between CD40LG and IL-6, as well as the downregulation of CD247, CD2, CD40LG, KLRB1, and RETN in the lungs of sepsis-induced ARDS mice, suggest their potential role in modulating the immune response and reducing inflammation in COVID-19 and sepsis. Here, KLRB1 is linked to COVID-19.