Furthermore, expression of Toll-like receptor 4 (TLR4) and NADPH oxidase 4 (NOX4) is significantly increased in HF, and either TLR4 or NOX4 knockdown inhibits ferroptosis by regulating ferroptosis-related proteins, suggesting that TLR4-NOX4 pathway might be a potential therapeutic target for HF (105). Here, TLR4 is linked to hydrops fetalis.