Previous studies have identified multiple Brn-3b target genes in cancer cells but whilst activation of target genes such as cyclin D1/CDK4 and repression of BRCA1 tumour suppressor are likely to contribute to growth and proliferation in cancer cells, the small heat shock protein, HSP27 was the main Brn-3b target gene, known to be associated with survival following drug treatment and increased metastasis. Here, CDK4 is linked to cancer.