Cancer is not one disease, but many—each with a specific set of underlying molecular abnormalities; the cancer-treatment paradigm is shifting toward selection of agents based on specific biological features of the individual patient’s disease. Fortunately, methods for profiling disease in individual patients are now commercially available, meaning that new generations of therapies targeted to specific molecular abnormalities can be more easily aligned to individual patients. This new approach to targeted therapy development results in an increasing number of clinical trials that are essentially “rare cancer” studies. The demand for reaching cancer patients to participate in “rare cancer” clinical trials increases every year, which adds significant challenges to conducting the trials. The Obama administration has pledged to increase cancer trial participation to 10% of adult patients from its current rate of 3-5%. In addition, the Director of the NCI will address the regulatory barriers that prevent timely completion of successful clinical research.