To assess the involvement of Notch proteins in the ER stress/UPR signaling network in T-ALL, ER stress induction by Tunicamycin treatment was performed in different human T-ALL cell lines, all constitutively expressing Notch1 and Notch3 at various levels (Supplementary Fig. S1a), and their survival was evaluated (Fig. 1a). This evidence concerns the gene NOTCH1 and acute lymphoblastic leukemia.