JAK1 and acute lymphoblastic leukemia: Since the above results show that IL7R is crucial for the transforming signals initiated by BCR-ABL1 in Ph+ ALL, we investigated whether inhibition of IL7R signaling using ruxolitinib, a JAK1/JAK2 kinase inhibitor, can interfere with the survival of BCR-ABL1-transformed cells or enhance the effect of kinase inhibitors on these cells.