TMX1 (thioredoxin related transmembrane protein 1) is a membrane-bound protein disulfide isomerase located in the endoplasmic reticulum that catalyzes dithiol-disulfide exchange reactions and formation/reduction of disulfide bonds in transmembrane proteins 1. As a key regulatory protein, TMX1 acts as a critical inhibitor of alternative triglyceride biosynthesis by binding to and controlling TMEM68/DIESL at the ER, thereby restricting triacylglycerol accumulation from diacylglycerol and membrane phospholipids 1. TMX1 participates in ER-associated degradation (ERAD) by acting on misfolded proteins and regulates ER-mitochondria contact sites and calcium flux 2. The protein functions as a negative regulator of platelet aggregation and coagulation, inhibiting phosphatidylserine exposure on both platelets and endothelial cells 3. In cancer contexts, TMX1 demonstrates tumor-suppressive properties in hepatocellular carcinoma by stabilizing FABP5 and inhibiting ferroptosis, while its downregulation correlates with poor prognosis in gastric cancer through DNA hypermethylation 45. TMX1 also influences immune cell infiltration and may serve as a therapeutic target in lung adenocarcinoma 6.