TCDD promotes the interaction of FAK with HEF1 and the phosphorylation of HEF1 through a Src/FAK pathway. (a) HepG2 cells were treated or not with TCDD (25 nM) for 24 h. Western blots of cell extracts (input) or cell extracts immunoprecipitated with FAK, HEF1 or IgG antibodies were performed with a HEF1 antibody. (b) HepG2 cells were treated with TCDD (25 nM) and/or PF-228 (10 μM) for 24 h. Western blots of cell extracts were performed with antibodies against actin or HEF1 (upper band: p115 and lower band: p105). (c) HepG2 cells were treated with TCDD (25 nM) and/or PP2 (10 μM) for 24 h. Western blots were performed with cell extracts using antibodies to: FAK pY397, FAK pY861, FAK pY925, HEF1 or E-cadherin. The right panel shows the quantification of three independent experiments. **P<0.01 and *P<0.05 as compared with controls.