FLT3/ITD is constitutively autophosphorylated in 32D cells expressing C/EBPα-ER. Total cellular protein extracts derived from 1 × 10⁷ 32D/α-ER cells transduced with the pBabeNeo vector, pBabeNeo-FLT3, or pBabeNeo-FLT3/ITD were immunoprecipitated with anti-FLT3 antibody. The immunoprecipitates were resolved by 8% SDS-PAGE and subjected to immunoblot analysis with antiphosphotyrosine antibody 4G10 (top). The same membrane was stripped and reprobed with anti-FLT3 antibody (bottom).