The function of ENSG00000161692 (DBF4B, DBF4B-CDC7 kinase regulatory subunit) is as follows. Regulatory subunit for CDC7 which activates its kinase activity thereby playing a central role in DNA replication and cell proliferation. Required for progression of S and M phases. The complex CDC7-DBF4B selectively phosphorylates MCM2 subunit at 'Ser-40' and then is involved in regulating the initiation of DNA replication during cell cycle. {ECO:0000269|PubMed:12065429, ECO:0000269|PubMed:15668232, ECO:0000269|PubMed:17062569}.