In December 2014, the European commission approved the first drug directed against a member of the PARP familiy (Poly ADP-Ribose Polymerases). Olaparib, a drug against ovarian cancer, has been developed by AstraZeneca and might become an important medicine very soon. Olaparib blocks PARP1 (see the Figure below showing the inhibitory effect of Olaparib on PARP1 measured with the PARP1 Chemiluminescent Activity Assay), an enzyme involved in cell repair, and is designed for ovarian cancer patients with certain hereditary gene mutations. It also has promise in treating other cancers, including breast and gastric tumors, opening up a substantial market opportunity. Olaparib is able to stop cancer cell growth in patients carrying inherited faults in the BRCA1 or BRCA2 genes (BReast CAncer 1 and 2 genes).