Western blot analysis of extracts from L-540 cells using Phospho-TNK1 (Tyr277) Antibody (upper and middle) or TNK1 (C44F9) Rabbit mAb #4570 (lower). The middle membrane was treated with calf intestinal alkaline phosphatase (CIP) before antibody probing. L-540 cells express a 58 kDa TNK1-C17orf61 fusion protein containing 466 amino acids from the amino terminus of TNK1 [Gu, T.L. et al. (2010) Leukemia, in press]. TNK1 kinase was constitutively activated in these cells.