SHP2 phosphorylation is increased in ALK⁺ ALCL. (A) Western blot analysis performed on human ALK⁺ ALCL (TS, SU-DHL-1, JB6, and COST), ALK- ALCL (OCI-Ly13.2, DL-40, and MAC2A) and healthy donor T cells and PBMCs with the indicated antibodies. (B) Western blot analysis performed on 293T cells transduced with a doxycycline-inducible lentivirus expressing PTPN1 or PTPN2. 293T-HEK cells were transfected with NPM-ALK and/or SHP2 vectors as indicated, induced with doxycycline for 48 hours, and then collected. Cell lysates were blotted with indicated antibodies. β-Actin was used as a loading control. (C) Competitive cell growth assay performed on TS and JB6 cells transduced with a retrovirus expressing empty vector, SHP2^wt, and SHP2^E76K or SHP2^D61Y mutant vectors cultured in presence of 40 nM crizotinib for indicated time. Data are represented as means ± SD of technical triplicates; **P = .0061 ****P < .0001, 2-way ANOVA followed by Dunnett's multiple comparisons test.