These techniques detected CNVs in 214 T-ALL patients (67 non-matched relapse and 147 diagnostic cases) and identified activating mutations in NT5C2 and/or inactivation of TP53 and/or duplication of chr17 (q11.2; q24.3) in 48% of T-ALL relapse samples. Here, TP53 is linked to acute lymphoblastic leukemia.