Human myoglobin has 152 residues. Two myoglobin variants were found. The myoglobin locus mapped to 22q11-22q13. The myoglobin gene is about 10.5 kb long and contains two introns as in the case with hemoglobin genes. Myoglobin may serve a variety of functions in muscular oxygen supply, such as O(2) storage, facilitated O(2) diffusion, and myoglobin-mediated oxidative phosphorylation.