Although significantly fewer than for pediatric ALL, backtracking studies have detected t(15;17)/PML/RARA and t(8;21)/RUNX1/RUNX1T1 fusion genes in neonatal blood spots or UCB of children or adolescents subsequently developing AML, indicating that these as a minimum can be initiated in utero [121,200,201,202,203]. Here, RUNX1 is linked to acute lymphoblastic leukemia.