Other plant-derived natural products (e.g., nicotine, epigallocatechin gallate, tanshinone, chlorogenic acid, resveratrol, emodin-6-O-β-D-glucoside, rosmarinic acid, isorhamnetin-3-O-galactoside, persicarin, forsythoside B, acteroside, and shikonin) can also inhibit HMGB1-related inflammation and immune dysfunction in various severe infections [35], and are likewise promising drug candidates for the treatment of patients suffering from COVID-19. Here, HMGB1 is linked to COVID-19.