In addition, the mouse contains conditional, floxed alleles for the oncogene, BrafV600E, and the tumour suppressor, Pten. In the Tyr-Cre mouse, Cre is fused to the oestrogen receptor, therefore only when treated with tamoxifen, will Cre result in BrafV600E activation and Pten loss. The gene discussed is PTEN; the disease is neoplasm.