Many researchers have supported that CDKN2A/B deletions in childhood ALL were associated with an increased probability of relapse and impaired outcome [17,18,19,21,24,25,26,27,28,29,30,31], whereas Mirebeau et al. [32], Kim et al. [33], and van Zutven et al. [34] concluded that the presence of the deletion was not a poor prognostic factor in childhood B-ALL. This evidence concerns the gene CDKN2A and precursor B-cell acute lymphoblastic leukemia.