NTN3 (netrin 3) is a secreted guidance molecule that functions as a ligand for the DCC dependence receptor, playing critical roles in both developmental and pathological contexts. In cancer biology, NTN3 promotes cell survival through DCC activation; elevated NTN3 expression has been observed in neuroendocrine neoplasms, small-cell lung cancer, and neuroblastoma, where it supports tumor growth 1. Blocking NTN3-DCC interaction using netrin-inhibiting antibodies suppresses pancreatic neuroendocrine neoplasm xenograft growth in vivo, with NTN3 expression inversely correlating with patient survival 1. NTN3 has also emerged as a potential biomarker in plasma extracellular vesicles for distinguishing early-stage lung adenocarcinoma from benign pulmonary nodules 2. During development, NTN3 contributes to axon guidance and plays a role in Hirschsprung disease pathogenesis as one of several genes involved in enteric neuron migration 3. Additionally, NTN3 accumulates in the detergent-insoluble proteome of Alzheimer's disease brains, suggesting involvement in protein aggregation pathology 4. These findings position NTN3 as a multifunctional protein with significance in developmental neurobiology, neurodegenerative disease, and cancer biology, representing a potential therapeutic target in neuroendocrine malignancies.