Additional Study Information: Major advances are being made in the treatment of cancer. One such advance involves the use of targeted treatments designed to work against specific molecular alterations in a given patients tumor. However, in most cases, we are not yet able to predict which patients will benefit from a specific targeted treatment, even if a tumor harbors the alteration that is the target of that treatment. Furthermore, although many patients benefit from targeted treatments for a period of time, the tumor will often become resistant to the treatment and start growing again at some point. The purpose of this study is to understand why certain patients respond to targeted treatments and others do not. The other major purpose of this study is to understand why targeted treatments stop working after initially helping. To do this, the researchers will collect a tumor biopsy before patients started a targeted treatment, and again the treatment initially helps but then stops working. In some cases, patients physicians will be given the results of part of the testing.