NT5DC2 (5'-nucleotidase domain containing 2) is a regulatory protein that functions as a negative modulator of catecholamine biosynthesis through its effects on tyrosine hydroxylase (TH) phosphorylation. The protein promotes dephosphorylation of TH, leading to decreased TH catalytic activity and reduced synthesis of dopamine, noradrenaline, and adrenaline 1. NT5DC2 can directly bind to both phosphorylated recombinant and endogenous TH in neuronal cells, and its overexpression decreases DOPA production by facilitating TH dephosphorylation in a phosphatase-like manner 1. Beyond its role in neurotransmitter regulation, NT5DC2 demonstrates significant oncogenic properties across multiple cancer types. In glioblastoma, NT5DC2 is preferentially expressed in glioma stem-like cells and promotes tumorigenesis by upregulating Fyn expression, with knockdown inhibiting tumor formation and prolonging survival 2. The protein serves as an independent prognostic factor in hepatocellular carcinoma, where high expression correlates with poor overall and relapse-free survival 3. In diffuse large B-cell lymphoma, NT5DC2 knockdown suppresses cell proliferation and induces apoptosis through p53 pathway regulation 4. NT5DC2 has also emerged as a potential biomarker in gastric cancer metastasis and melanoma immunotherapy response prediction 56.