In 1994 an ICR team led by Michael Stratton discovered the gene BRCA2, which has been linked to breast cancer, prostate cancer and ovarian cancer. Alan Ashworth's team in the Breakthrough Breast Cancer Research Centre at the ICR established the connection between mutations in the BRCA2 gene and the operation of DNA repair pathways in cancer cells. This later led to the development of a PARP inhibitor drug, olaparib, which targets the DNA repair pathways of cancer cells. A Phase I trial of olaparib found in June 2009 that tumours shrank or stabilised for more than half of patients with BRCA1 and BRCA2 mutations. It is believed that the drug may also be useful in other patients whose cancer it is linked to an error in their DNA repair pathway.