We demonstrated DNA demethylation of the promoter sequences of selected antigen-presenting machinery genes (TAP-1/LMP-2, TAP-2) upon IFNγ treatment both in the MHC class I-deficient tumour cell line TC-1/A9 (Fig. 2a) and in the prostate cancer cell line TRAMP-C2 (Fig. 2b). This evidence concerns the gene PSMB9 and prostate cancer.