TLR4 and hydrops fetalis: Chen et al. found that TLR4 or NOX4 knockdown in rats significantly improved left ventricular remodeling and reduced myocardial cell death in HF rats induced by aortic banding, confirming that toll-like receptor 4 (TLR4)/NADPH oxidase4 (NOX4) participates in regulating autophagy and ferroptosis-mediated myocardial cell death (Chen et al., 2019b).