This limited expression of ETV6-RUNX1 during early hematopoietic development mimicked human ETV6-RUNX1 preleukemic biology, where ETV6-RUNX1 expression is not detected in progenitor B-cells of healthy children carrying preleukemic clone [29, 30], and conferred a low risk of developing pB-ALL after exposure to common pathogens corroborating the low incidence in humans and facilitated the identification of genetic basis of the clonal evolution of an ETV6-RUNX1 preleukemic clone to pB-ALL. Here, ETV6 is linked to acute lymphoblastic leukemia.