The p.Q117* truncating mutation identified here in a single male patient (194) suggests a tumor suppressor role for USP9X in T-ALL, and the strong decrease in apoptosis observed following knockdown of the gene and chemotherapy drug treatment further corroborates the anti-oncogenic role of USP9X in childhood T-ALL and suggests a possible involvement on treatment resistance. Here, USP9X is linked to acute lymphoblastic leukemia.