RUNDC3A (RUN domain containing 3A) is a protein involved in small GTPase-mediated signal transduction that functions as a potential RAP2A effector in neuronal cells. Primary function: RUNDC3A regulates SNAP25 expression, which stabilizes Akt kinase through modulation of monoubiquitination 1. This RUNDC3A/SNAP25/Akt signaling axis promotes tumor progression and chemoresistance across multiple neuroendocrine neoplasms (NENs), including gastric, intestinal, lung, and pancreatic neuroendocrine carcinomas 1. Mechanism: RUNDC3A participates in synapse formation, neurotransmission, and mitochondrial metabolism pathways 2. The gene is subject to chr17 alterations and epigenetic modifications; its antisense RNA (RUNDC3A-AS1) functions as a competing endogenous RNA regulating the Warburg effect in colorectal cancer by controlling glycolysis and hexokinase II activity 3. Disease relevance: RUNDC3A alterations are identified in pediatric pineal germinomas 4 5, thyroid cancers 6 7, and bipolar disorder 2 2. RUNDC3A resides in a region deleted in rare frontotemporal dementia cases 8. Clinical significance: RUNDC3A/SNAP25/Akt axis represents a novel therapeutic target for NENs with chemoresistance. Further experimental validation is needed to establish RUNDC3A as a functional biomarker for prognosis and treatment prediction across multiple cancer types.