INMT (indolethylamine N-methyltransferase) is a Class I methyltransferase enzyme that catalyzes N-methylation of diverse substrates including tryptamine, serotonin, and dopamine 1. Beyond its classical role in amine metabolism, INMT functions as a thioether S-methyltransferase critical for detoxifying selenium and other chalcogen compounds, converting dimethylselenide to trimethylselenonium ion for urinary excretion 2. The enzyme recognizes electrically neutral substrates through hydrophobic residues in its active center, with L164 being essential for both selenium and N-methyltransferase activities 2. Clinically, dysregulation of INMT is linked to multiple pathological conditions. In kidney disease, voclosporin-induced acute kidney injury involves INMT downregulation; transgenic mice overexpressing renal proximal tubule INMT showed preserved peroxisomal and mitochondrial integrity with reduced reactive oxygen species and apoptosis 3. In castration-resistant prostate cancer, INMT upregulation promotes cancer progression through detoxification of anticancer metabolites, with SMYD3 serving as its epigenetic regulator 4. Pulmonary fibrosis studies identify INMT-expressing fibroblasts as anti-fibrotic cells that can shift toward pro-fibrotic phenotypes 5. Notably, INMT is not essential for endogenous dimethyltryptamine biosynthesis in rodents, suggesting alternative metabolic pathways 6. These findings position INMT as a promising therapeutic target with applications in detoxification, cancer, and fibrotic disease management 1.