TNF and COVID-19: MCs also produce de novo lipid mediators such as prostaglandins (PGD2, PDE2), leukotrienes (LTB4, LTC4, LTD4), platelet-activating factor (PAF), cytokines (e.g., TNF, IL-6, IL-4, IL-5, IL-1β, IL-10, IL-13), and chemokines (e.g., CCL1, CCL2, CXCL1, CXCL8) [58,59,60,62], many of which are now known to be associated with the “cytokine storm” observed in severe COVID-19.