5AC treatment combined with CpG ODN (in 5AC only-treated mice, the upregulation was not significant) moderately (much less than can be seen upon in vitro IFNγ treatment) increased the expression of the B7-H1-negative regulator on tumour cells, which is known to be regulated through the IFNγ-inducible IRF-1 factor (Lee et al, 2006). This evidence concerns the gene IRF1 and neoplasm.