WNK2 and infection: Studies have identified the potential mechanism of QFPDD in the treatment of COVID-19, mainly by acting on key molecules such as interleukin, mitogen-activated protein kinase, and TNF (tumor necrosis factor), affecting the toll-like receptor pathway, TNF signaling pathway, and interleukin signaling pathway, exerting immunomodulatory, anti-infection, and anti-inflammatory storm effects (Niu et al., 2020; Niu et al., 2021).