Rapamycin effects on Akt, mTOR and its downstream targets in MCF10A cell lineage. Panel A: Immunoblot analysis of phospho-mTOR, phospho-Akt, phospho-4E-BP1, phospho-p70S6K (Thr389 and Thr421/Ser424), phospho-S6RP, and phospho-STAT3 (Ser727) protein levels following the treatment of each cell with 100 nM rapamycin for 1 and 24 h. Panel B: Scanning laser densitometry analysis of immunoblot band density. Rapamycin was least effective in inhibiting phospho-p70S6K and phospho-S6RP in the 10CA1a tumor cells.