NOX4 and cancer: The transmembrane receptors examined in this study—NADPH-oxidase 4 (NOX4), Epidermal Growth Factor Receptor (EGFR), Platelet-Derived Growth Factor Receptor (PDGFR), and Organic Cation/Carnitine Transporter Novel 2 (OCTN2)—are interconnected in pathways governing oxidative stress regulation, cell proliferation, and drug transport; thus, influencing cancer progression.