ARTN (artemin) is a neurotrophic growth factor belonging to the glial cell-derived neurotrophic factor (GDNF) family that supports the survival of sensory, sympathetic, and dopaminergic neurons 1. ARTN functions by binding to its co-receptor GFRA3, leading to autophosphorylation and activation of the RET receptor tyrosine kinase, which subsequently activates downstream signaling pathways including AKT 1. Beyond its neurotropic functions, ARTN has emerged as an important oncogenic factor that promotes tumor progression, metastasis, and drug resistance across multiple cancer types 1. In breast cancer, ARTN is estrogen-regulated and mediates antiestrogen resistance by increasing BCL-2 expression and promoting estrogen-independent growth 2. ARTN expression correlates with increased tumor size, rapid relapse, and shorter survival in hepatocellular carcinoma patients 1. The protein is also secreted by tumor-induced erythroblast-like cells in the spleen, facilitating cancer progression through systemic circulation 3. Additionally, ARTN appears to play roles in inflammatory conditions, with elevated levels observed in long COVID patients with chr1 fatigue syndrome and serving as a mediator in the causal relationship between psoriasis and psychiatric disorders 45.