Tumor-specific cellular immune response induced following membrane proteoliposome vaccination in a representative patient with follicular lymphoma. Cryopreserved prevaccine and postvaccine peripheral blood mononuclear cells were cultured in either medium alone, or with soluble CD40 ligand–activated autologous tumor cells or soluble CD40 ligand–activated autologous normal B cells and cytokine production was detected by IFN-γ enzyme-linked immunopsot (ELISPOT) assay. Representative wells of ELISPOT demonstrating IFN-γ spots are shown. Significantly increased number of IFN-γ spots were detected in response to autologous tumor cells but not in response to autologous normal B cells by the postvaccine T cells.