TLR4 and pemphigus foliaceus: Our previous studies showed that TLR4–MyD88 signaling mediates NADPH oxidase activation in neutrophils and lung vascular endothelial cells in response to hemorrhagic shock and LPS.37, 51, 52 In the current study, we showed that the PF/tissue damage activation of TLR4–MyD88 signaling results in increases in ROS production through the activation of NADPH oxidase in Mφ.