SLC6A4 and malignant colon neoplasm: Recently, Ye et al. demonstrated that inhibiting SERT with sertraline promotes the uptake and catabolism of extracellular tryptophan in colon cancer, both in vitro and in vivo, in a mechanism that suppresses mTOR serotonylation, leading to mTOR inactivation and increased tryptophan uptake and catabolism, that increases serotonin biosynthesis and oncogenic metabolite kynurenine production [52].