The human gene for nuclear protein BM28 (CDCL1), a new member of the early S-phase family of proteins, maps to chromosome band 3q21.

BM28, a newly recognized human nuclear protein, possibly plays an important role in two crucial steps of the cell cycle e.g. the onset of DNA replication and cell division. It shows significant similarity to members of a recently defined family of early S-phase proteins. Using total plasmid DNA containing the complete coding sequence of the BM28 gene (CDCL1, for cdc-like 1) as a probe for fluorescence in situ hybridization, we have mapped the gene to chromosome band 3q21. This region is involved in specific structural chromosome aberrations found in acute myeloid leukemia (AML). Based on the function of BM28 and the chromosomal location of its gene, CDCL1 might prove to be a candidate for an oncogene affected by the chromosomal breaks and playing a pathogenetic role in AML.