By triggering the over-expression of MHC-I molecules and costimulatory molecules, in vitro treatment with a combination of hIFN-γ and GGTI-298 modifies LB1319-MEL melanoma cells such that they acquire some characteristics of stimulatory APC and become more efficient stimulator cells able to activate CD8 T lymphocytes from PBMC of HLA-compatible HD. The gene discussed is PGGT1B; the disease is melanoma.