SLC7A1 encodes a high-affinity, low-capacity transporter for cationic amino acids (arginine, lysine, and ornithine) across the plasma membrane 123. The protein plays a critical role in cellular arginine uptake, particularly in cancer cells that have become arginine-auxotrophic due to suppressed urea cycle enzymes like ASS1 12. Mechanistically, SLC7A1 facilitates arginine transport essential for protein synthesis, polyamine production, and immune cell function 34. The transporter's localization is regulated by the retromer complex, with VPS35 oxidation controlling SLC7A1 plasma membrane positioning in response to ROS levels 5. In disease contexts, SLC7A1 overexpression promotes tumor progression in hepatocellular carcinoma, non-small cell lung cancer, osteosarcoma, and epithelial ovarian cancer by supporting metabolic reprogramming and conferring chemotherapy resistance 1267. Conversely, SLC7A1 supports beneficial immune responses by enabling CD8+ T cell differentiation into tissue-resident memory cells through arginine uptake 4. Clinically, SLC7A1 represents a promising therapeutic target, with inhibition strategies showing efficacy in preclinical cancer models and potential for combination with dietary arginine restriction or senolytic therapies 126.