Figure 11.

Illustration of the antagonistic effects that melatonin has on TLR and NLR functions in severe COVID-19 (from Figure 3A). The large red stars indicate the TLR and NLR that are antagonized (the question mark indicating that evidence for this antagonism is provisional). The small red stars indicate the synergisms that are eliminated as a result of the receptor antagonisms. By downregulating TLR2, TLR4, TLR9, NLRP3 and, possibly, NOD2 as well, almost all of the innage receptor synergisms driving cytokine overproduction are eliminated, effectively returning the system to normal.