MYC and breast adenocarcinoma: Mnt competes with Myc for dimerisation with their mutual obligate partner Max and for binding at E-box sites in an overlapping set of target genes.22 Mnt overexpression can suppress Myc-dependent cell proliferation24 and tissue-specific loss of Mnt in mice resulted in mammary adenocarcinomas and T-cell lymphomas.8, 25, 47 Thus Mnt has been regarded as a tumour suppressor.