Importantly, high-risk BCR-ABL1 negative ALL cases with deletion of IKZF1 and poor outcome have a gene expression profile significantly similar to that of Ph+ALL (“BCR-ABL1-like” ALL) [29, 33], suggesting that these cases may harbor alternative genetic events leading to aberrant activation of tyrosine kinase signaling pathways similar to those downstream of BCR-ABL1. Here, IKZF1 is linked to acute lymphoblastic leukemia.