Although previous reports have shown that MCMs serve as potential targets for tumor therapy, an important problem should be pointed out: partial suppression of MCMs function can give rise to increased genomic instability and DNA damage.11, 17 MCM4 knockout mice display genomic instability and mice with sustained, partially defective MCMs function display increased cancer risk.57, 58, 59, 60 We provide here that SVA or ARO reduces MCM7 and RB protein expressions, induces chromosome instability and gives rise to apoptosis in various tumor cells. This evidence concerns the gene MCM4 and cancer.