Cell growth induced by E-cad knockdown can be inhibited by EGFR tyrosine kinase inhibitor. Sulforhodamine B (SRB) assay was used for cell growth determination. E-cad siRNA-transfected PCI-37A and 686LN cells were re-seeded in a 96-well plate 24 hrs after the transfection. To check whether activation of EGFR contributed to cell proliferation, reseeded transfected cells were treated with 1 μM EGFR-specific tyrosine kinase inhibitor erlotinib for 48 or 72 hrs followed by fixation with 10% trichloroacetic acid and SRB assay. The OD at 510 nm was determined as absorbance value. The results showed that E-cad knockdown clearly induced cell growth, which, however, could be inhibited by treatment with 1 μM erlotinib. Data presented are 1 of 3 repeated independent experiments. Error bars represent standard deviation.