Nutlin-3a treatment of mantle cell lymphoma, an aggressive type of B-cell non-Hodgkin lymphoma with cyclin D1 overexpression, decreased AKT phosphorylation at Ser473, causing p53-dependent AKT/mTOR pathway inhibition mediated by AMPK (AMP-activated protein kinase). The gene discussed is AKT1; the disease is mantle cell lymphoma.