Downregulation of EF1α expression diminished the clonogenic potential of HCC1937 and SkBr3 cells, suggesting that EF1α regulates this aspect of breast cancer cell phenotype; suppression of Akt activity by Akt inhibitors induced only a modest but not statistically significant decrease of colony formation and combining the EF1α siRNA with Akt inhibitors had only a modest additive effect. The gene discussed is AKT1; the disease is breast carcinoma.