Remarkably, ERE73 (1 + 2) MT-ARF (−13) and ERE73 (3 + 4) MT-ARF (−13) mutants displayed lower promoter activity than their analogous wild-type constructs exclusively in the cancer cell lines (Saos-2, 5637, DLD-1, and HLF), while no significant downregulation of promoter activity was observed in human normal fibroblasts (HFFs) (Figure 2C). Here, CDKN2A is linked to cancer.