LDHB protein, encoded by the LDHB gene, is a subunit of the lactate dehydrogenase enzyme, which catalyzes the interconversion of pyruvate and lactate with the concomitant interconversion of NADH and NAD+ in a post-glycolysis process. This enzyme exists in five different forms, each composed of four subunits, with LDHB subunits combining with LDHA subunits to form various isozymes. The LDHB gene is located on chromosome 12p12.1 and encodes a protein of 334 amino acids. Mutations in the LDHB gene can lead to lactate dehydrogenase B deficiency, but this condition typically does not cause any physical signs or symptoms.