The NME4 antibody is a crucial tool for studying the NME/NM23 nucleoside diphosphate kinase family, particularly the NME4 protein (also known as NM23-H4). NME4 is a mitochondrial enzyme involved in diverse cellular processes, including apoptosis, mitochondrial membrane dynamics, and nucleotide metabolism. Unlike other NME family members, NME4 localizes to the intermembrane space of mitochondria, where it interacts with cardiolipin and participates in maintaining mitochondrial cristae structure during apoptosis. It also exhibits nucleoside diphosphate kinase activity, contributing to nucleotide homeostasis essential for mitochondrial DNA synthesis and energy metabolism. Research links NME4 to cancer progression, neurodegenerative diseases, and metabolic disorders, though its role appears context-dependent, acting as both a tumor suppressor and promoter in different cancers. The NME4 antibody enables detection and quantification of endogenous NME4 protein levels via techniques like Western blotting, immunohistochemistry, and immunofluorescence. Its specificity is validated through knockdown/knockout controls, ensuring reliable results in studies exploring mitochondrial dysfunction, cancer biology, or metabolic pathways. Recent studies also implicate NME4 in mitophagy and ferroptosis regulation, expanding its relevance in cell death mechanisms. As mitochondrial dysfunction underpins many diseases, this antibody remains vital for unraveling NME4's multifaceted roles in health and disease.