GPX4 and neoplasm: The impact of exosomal miRNAs on tumor redox homeostasis is largely mediated through key antioxidant and oxidative stress signaling pathways, including the nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1(Keap1) pathway, and the glutathione peroxidase 4 (GPX4)-related ferroptosis regulation and TGFβ1-ROS axis.