PDCD1 and diffuse large B-cell lymphoma: Our previous study also demonstrated that the stimulation of PD-1 could activate the intracellular AKT/mTOR pathway by the PD-1/PD-L1 axis and that coexpression of PD-L1 and p-AKT is associated with poor prognosis in diffuse large B-cell lymphoma (DLBCL) 15.