Testing for specific mutations has already entered the clinical oncology landscape. Cancer drugs such as Zelboraf (vemurafenib, Roche AG and Daiichi Sankyo Co. Ltd.) and Xalkori (crizotinib, Pfizer Inc.) target patients with specific mutations. Earlier in development, some clinical trials, such as for Exelixis Inc.'s cabozantinib, have focused on specific mutations across a variety of tumor types.