To investigate which RTK would stimulate the highest PDK1 activity, breast cancer cell lines HCC1954, BT20, MCF7, and T47D were treated with IGF-I, insulin, EGF or TNF-α, and phosphorylation levels of AKT and p70S6K were determined by western blot analysis (Figure 1 and Figure S1). This evidence concerns the gene RPS6KB1 and breast cancer.