GM-CSF, IL-4 with TNF- or CD40L are the most effective combinations for augmenting allostimulatory activy of AML cells. Allogeneic MLR assays were performed as described in Materials and Methods. Freshly isolated (▪), GM + IL-4 + TNF-–cultured (▧), and GM + IL-4 + CD40L–cultured (▨) AML cells from five patients were compared for their ability to stimulate PBMNC of a normal allogeneic donor. Results represent the mean ± SD of triplicate cultures.