Lactate dehydrogenase
Each LDH molecule is made of four subunits. There are somewhat different types of LDH in different tissues. The main type in the lungs has two M subunits and two H subunits (2H2M). The M and H subunits are coded by two different genes. The M subunit is coded by LDHA on human chromosome 11, and the H subunit is coded by LDHB on chromosome 12.