To investigate the potential role of USP7 in the control of SF3B1, we treated T-ALL cells with the global deubiquitinase inhibitor PR619 and the USP7 inhibitor P5091 as well as with compounds inhibiting the prooncogenic deubiquitinases USP1 (ML323) and USP14/UCHL5 (b-AP15) (39–43). Here, USP7 is linked to acute lymphoblastic leukemia.