Effect of PKCη on cell growth. A, MCF-7 cells were transfected with control non-targeting siRNA or PKCη siRNA and total cell extracts were used for Western blot analysis. Actin was used as a loading control. B, Clonogenic assay was performed with MCF-7 cells transfected with either control non-targeting siRNA or PKCη siRNA as described in the Materials and Methods. C, Quantification of the number of colonies as determined by the clonogenic assay. The results are representative of 3 independent experiments. *P < 0.05 using paired Student t test. D, MTT assay was performed with T47D cells transfected with control, non-targeting siRNA or PKCη siRNA as described under Materials and Methods. The results are representative of 3 independent experiments. **P < 0.01 using paired Student t test. E, MTT assay was performed with DCIS cells transfected with control non-targeting siRNA or PKCη siRNA as described under Materials and Methods.