LDHB (lactate dehydrogenase B) is a key metabolic enzyme that catalyzes the reversible conversion of pyruvate to lactate with concomitant NAD+/NADH interconversion 1. LDHB exhibits cell-type specific expression, particularly in pancreatic β cells where it regulates lactate levels and basal insulin secretion 1. The enzyme plays critical roles in cellular metabolism through multiple mechanisms: it restricts glucose-6-phosphate dehydrogenase (G6PD) activity by direct protein interaction, leading to NADPH depletion and promoting disulfidptosis in exhausted CD8+ T cells 2. In dendritic cells, LDHB contributes to glycolytic flux that drives STING signaling for antitumor immunity 3. LDHB is overexpressed in various cancers including bladder cancer as part of the Warburg effect 4 and acute myeloid leukemia where it supports aerobic glycolysis 5. Disease relevance includes associations with ischemic stroke risk 6, acetaminophen-induced liver injury through mitochondrial lactate metabolism 7, and atherosclerosis progression via foamy macrophage ferroptosis 8. Clinically, LDHB represents a potential therapeutic target in cancer immunotherapy, metabolic disorders, and cardiovascular diseases, with Mendelian randomization studies linking low LDHB expression to elevated fasting insulin levels 1.