NCK2 is an adaptor protein that functions in signal transduction by linking tyrosine-phosphorylated receptors to downstream effectors through its SH2 and SH3 domains 1. Despite structural similarity to NCK1, NCK2 has distinct, non-redundant cellular functions 12. The protein plays important roles in cancer progression, particularly in melanoma where NCK2 overexpression promotes cell proliferation, migration, and invasion by modulating tyrosine phosphorylation levels and cytoskeletal dynamics 3. NCK2 expression is consistently elevated in metastatic cancer cell lines compared to primary counterparts 3. In spermatogonial stem cells, NCK2 interacts with OIP5 to regulate self-renewal and apoptosis through cell cycle progression pathways 4. NCK2 also mediates angiogenesis through the Slit2/Robo signaling pathway in endothelial cells 5. Structurally, the NCK2 SH2 domain contains a unique C-terminal antiparallel β-sheet and can bind multiple phosphorylated ephrinB fragments with different mechanisms 6. Genome-wide association studies have implicated NCK2 as a novel Alzheimer's disease risk gene 78, highlighting its potential clinical significance in neurodegeneration.