PSEN1 and acute lymphoblastic leukemia: While gamma-secretase and PSEN1 inhibitors are promising candidates for the treatment of T-ALL/LBL patients with NOTCH1 pathway mutations26–29, pharmacological inhibition of the JAK/STAT pathway is significantly more complex due to the presence of oncogenic mutations in multiple pathway members as well as specificity and selectivity issues affecting inhibitors against STAT proteins8–10.