PAX5 and B-cell acute lymphoblastic leukemia: Another important function of Pax5 is to suppress B cell tumorigenesis in mice (Cobaleda et al., 2007) and humans (Mullighan et al., 2007), where heterozygous PAX5 mutations prominently contribute to the development of B cell acute lymphoblastic leukemia (Gu et al., 2019).