An imbalance in signalling from toll-like receptor (TLR) pathways, with the myeloid differentiation primary response protein (MyD88) pathway predominating over the TIR domain-containing adapter molecule 1 (TICAM-1, also known as TRIF) pathways, might further increase NLRP3 activation.48 Signalling downstream of IL-1 family receptors, including the IL-33 receptor ST2, and downstream of membrane TLRs, can activate MyD88 and elicit inflammation; whereas TRIF-mediated pathways downstream of endosomal TLRs would be expected to mount antiviral interferon responses and protect against coronaviruses.48, 49 Although coronaviruses are single-stranded RNA viruses that are predicted to bind directly to endosomal TLR7 and TLR8, and indirectly to TLR3 (using double-stranded RNA replication intermediates), aberrant inflammation induced by coronaviruses might instead involve membrane-expressed TLR2, as suggested by virus spike protein interactions with heparan sulphate-enriched regions of TLR2 in studies of the mouse hepatitis coronavirus.50 A predominance of MyD88 signalling over TRIF signalling would lead virus-exposed cells to produce high amounts of IL-1β, and NF-κB-induced cytokines and chemokines (eg, TNF, IL-8, IL-6, IL-12p40, IL-23, CCL2) rather than interferons, IL-12p35 and IL-12p70.30, 49, 50