To investigate the potential role of Usp9X in regulating MPNST cell survival, we first examined the effects of inhibiting Usp9X enzymatic activity with the deubiquitinase inhibitor, WP1130, a pharmacological inhibitor of Usp9X known also as Degrasyn6, on three NF1 patient-derived MPNST cell lines (ST88-14, T265-2c and 90-8). Here, USP9X is linked to neurofibromatosis type 1.