NDUFB2 is an accessory subunit of mitochondrial Complex I (NADH dehydrogenase), essential for oxidative phosphorylation and mitochondrial electron transport 1. As a structural rather than catalytic component, NDUFB2 facilitates NADH-to-ubiquinone electron transfer within the respiratory chain 2, supporting cellular energy production through ATP synthesis. NDUFB2 is responsive to mitochondrial stress, with its expression regulated by the mitochondrial unfolded protein response through CHOP-containing promoter elements 2. Dysregulation of NDUFB2 associates with multiple pathological conditions. Elevated NDUFB2 expression occurs in Gram-negative sepsis 3, venous thromboembolism with liver cirrhosis 1, and glioblastoma, where it functions as a risk gene 4. Conversely, NDUFB2 downregulation appears in inflammatory bowel disease as part of broader mitochondrial Complex I dysfunction and oxidative phosphorylation disruption 5, and in lymphocytic esophagitis accompanied by metabolic dysregulation 6. Additionally, NDUFB2 serves as a hub gene in Alzheimer's disease pathogenesis 7 and 8. These findings suggest NDUFB2 as a potential biomarker for disease diagnosis and progression monitoring, with therapeutic implications for conditions involving mitochondrial dysfunction and oxidative stress.