AKR1C4 (Aldoketoreductase 1C4) is a multifunctional oxidoreductase that plays a crucial role in maintaining metabolic balance and regulating the conversion of biologically active substances into their active or inactive forms in the human body. AKR1C4 is involved in the metabolism of various steroid hormones, including androgens, estrogens, and progestins. It converts these hormones into their active or inactive forms, thereby influencing their biological activity and effects in the body. In addition to steroid hormones, AKR1C4 also participates in prostaglandin metabolism. Prostaglandins are essential biologically active lipids involved in various physiological and pathological processes, such as inflammation, pain, and vasoconstriction. AKR1C4 can also metabolize certain drugs, affecting their efficacy and clearance rate. This is crucial for understanding the pharmacokinetics and pharmacodynamics of drugs in the body. As an NADPH-dependent oxidoreductase, AKR1C4 plays a role in maintaining redox balance within cells, helping to protect them from oxidative stress damage. Recent studies have found abnormal expression of AKR1C4 in various cancers, such as prostate cancer and breast cancer. This makes AKR1C4 a potential disease marker and therapeutic target. By modulating AKR1C4 activity, it may be possible to control cancer development and improve treatment outcomes.