Five long-term responders contributed 14 specimens to explore clonal heterogeneity. Genomic alterations with activating effect on mTOR signaling were detected in 11 of 14 specimens, offering plausible explanation for exceptional treatment response through alterations in two genes (TSC1, MTOR)....Clinical features for five patients with long-term response to temsirolimus [n=4] or everolimus [n=1] are summarized in table 1.