ATIC and VASP phosphorylation is dependent on NPM-ALK kinase activity. (A) Phospho-tyrosine containing proteins were first immunoprecipitated (IP) with a specific anti (pTyr) antibody and subsequently blotted with the indicated antibodies. (B) Lysates from ALK⁺ ALCL cell lines (TS and SU-DHL1), treated with small-molecule ALK inhibitor (CEP14083) or a control compound (CEP11988), were immunoprecipitated and blotted with the indicated antibodies. (C) Total lysates from doxycycline-treated TS TTA A5 cells (1 mg/mL for 84 and 96 hours) were IP with a specific anti-ATIC or anti-VASP antibody and blotted with anti-ALK antibody. (D) Total proteins from TS cells (300 nM of CEP14083 or CEP11988) were IP with a specific anti-ATIC or anti-VASP antibody and blotted with anti-ALK antibody.