PLK1 and neoplasm: CDC7 is a serine/threonine kinase that plays a critical role in the initiation of DNA replication by phosphorylating the MCM 2–7 complex, which is required for genome duplication.[30] As expected, both PLK1 inhibitor and CDC7 inhibitor combined with oxaliplatin arrested tumor cells at G2/M phase (Figure S4D, Supporting Information).