Next, to investigate whether the activation of Src/ERK/Akt/mTOR kinases were key elements of the leptin induced proliferation in 1321N1 astrocytoma cells, they were incubated in the absence or presence of an optimal concentration of human recombinant leptin (0.5 μM) at different times. Here, MTOR is linked to astrocytoma (excluding glioblastoma).