Changes in phosphorylation of CDCP1-Tyr-734 and FAK-Tyr-861 are inversely related during changes in attachment of HeLa CDCP1 cells. Lysates from HeLa CDCP1 cells undergoing either de-adhesion induced by EDTA over 45 min or re-adhesion over 45 min (after suspension growth for 30 min) were analyzed by Western blot analysis using antibodies against p-FAK-Tyr-861 (which also recognizes p-CDCP1-Tyr-734 (20)), CDCP1 (#4115), FAK, and tubulin. A, HeLa CDCP1 clone 2 cells undergoing de-adhesion. B, HeLa CDCP1 clone 3 cells undergoing de-adhesion. C, HeLa CDCP1 clone 2 cells undergoing re-adhesion. D, HeLa CDCP1 clone 3 cells undergoing re-adhesion. The data in A–D are representative of two independent experiments.