NOL3 (nucleolar protein 3) functions primarily as an apoptosis repressor that inhibits multiple cell death pathways through distinct molecular mechanisms 1. The protein blocks extrinsic apoptotic pathways by preventing death-inducing signaling complex (DISC) assembly and by sequestering caspase-8, while inhibiting intrinsic apoptosis through BAX inactivation and prevention of mitochondrial dysfunction 1. NOL3 also functions as a cytosolic calcium buffer, maintaining calcium homeostasis to prevent calcium-mediated cell death 1. Beyond apoptosis regulation, NOL3 promotes cell proliferation through activation of the PI3K/Akt pathway in bladder cancer cells 2. Paradoxically, NOL3 appears to have context-dependent roles, as deletion in mice leads to myeloproliferative neoplasms resembling primary myelofibrosis through JAK-STAT activation 3. In cancer contexts, NOL3 is associated with tumor progression, metastasis, and chemotherapy resistance in colorectal cancer, where it promotes epithelial-mesenchymal transition and glycolysis while creating an immune-desert tumor microenvironment 4. Clinically, NOL3 mutations cause familial cortical myoclonus, a movement disorder characterized by adult-onset progressive myoclonus without seizures 5, and NOL3 serves as a prognostic biomarker in colorectal cancer 6.