PTPN2 alterations. (A) PTPN2 deletions as identified by array CGH. Seven patients harboring deletions of the entire PTPN2 locus are represented. (B) Corresponding MLPA analyses. Patients UPNT516, UPNT383, UPNT242, and UPNT255 show monoallelic deletion of PTPN2, whereas patients UPNT528, UPNT533, and UPNT546 demonstrate biallelic deletions. (C) Quantitative real-time reverse transcription-polymerase chain reaction analysis of PTPN2 expression in T-ALL cases with (Del) or without (WT) PTPN2 deletion. GAPDH, glyceraldehyde-3-phosphate dehydrogenase.