Abstract: This invention provides novel methods of detecting or treating aberrant cell cycle regulation associated with expression of a nuclear protein encoded by a gene that is linked to map position 8q22.3 of the human genome, and to novel reagents that are useful therefor. More particularly, the invention provides novel nucleic acid and proteinaceous probes, for detecting a gene that is linked to map position 8q22.3 of the human genome or the expression products thereof, wherein expression or elevated expression of said gene is associated with the appearance or occurrence of tumors associated with cancer, DNA damage and progesterone-receptor-mediated effects on cells. The invention also provides reagents and methods for detecting or modulating the expression products of the gene, such as, for example, in the diagnosis or treatment of cancer, cellular proliferation, DNA damage or progesterone receptor-mediated effects on cells.