The phosphorylation status of the mTOR target, p70S6K, measured at 1 month of treatment, correlates with obtainment of clinical response. Proteins extracted from peripheral blood cells, collected at baseline (D0) and at 1 month of treatment (D30), were subjected to SDS-PAGE electrophoresis and Western blotting and probed with antibodies against the total and phosphorylated form of p70S6K; tubulin was used for loading normalization. Top, 5 patients who showed a major-to-moderate clinical response; bottom, 5 patients who were defined as nonresponders.