IL6 and infection: Whereas SAR-CoV-2 enhanced proinflammatory cytokine levels via suppressing IRAK3 expression in macrophages and monocytes, the in vitro infection with Middle East respiratory syndrome coronavirus (MERS-CoV) glycoprotein suppressed TNF-α and IL-6 protein production in macrophages through mediating induction of IRAK3 expression [104, 105].