The potential mechanism of action of HXZQ for COVID-19 is inhibiting SARS-CoV-2 replication, improving immune, and anti-inflammatory, mainly by acting on 3CLpro (115), PTGS2, AR, HSP90AB1, CAMSAP2, PPARG, NOS2, and other targets (116–118). Here, NOS2 is linked to COVID-19.