Like its chaperone CD147, MCT4 is hypoxia-dependent and CD147-MCT4 co-overexpression is regarded as unfavorable prognostic factor in cancers associated with hypoxia, a common feature of solid tumors but also a major component of the bone marrow microenvironment crucial in leukemia progression (14–18). The gene discussed is SLC16A3; the disease is leukemia.