RPS6KB1 and neoplasm: SESN2 inhibits mTOR-dependent phosphorylation of p70S6K and 4E-BP1,(6) and knockdown of SESN2 resulted in the activation of mTOR signaling indicating that the important role of SESN2 on mTOR inhibition.(30) Our results from western blotting demonstrated that mTOR was down-regulated by fisetin treatment in HNCCs consistent with other previous studies showing tumor inhibiting potentials of fisetin through mTOR pathway.(24,31,32) These results suggest that fisetin-induced apoptotic potentials is through SESN2/mTOR signaling axis.