TLR4 and severe acute respiratory syndrome: Oxidized phospholipids that accumulate in HPAI and SARS-CoV infections also likely contribute to ALI and hypercytokinemia (“cytokine storm”) by signaling though toll-like receptor 4 (TLR4) and TRIF/TICAM1 in macrophages, activating NF-kB and inducing IL6 [70].