BCR-ABL positive acute lymphoblastic leukemia (ALL) cell survival is strongly dependent on the IRE1α-XBP1 branch of the Unfolded Protein Response (UPR). In the study at hand, we have focused on exploring the link between BCR-ABL1 and IRE1α to better understand whether a simultaneous pharmacological inhibition of both pathways could represent a beneficial therapeutic strategy in Philadelphia positive (Ph+) ALL. Therefore, the effect on the phosphoproteome of two inhibitors (MKC-8866 and Nilotinib) as well as a combination of both compounds was analysed in this study.