In the United States, biological material derived from humans can be patented if it has been sufficiently transformed. In litigation that was famous at the time, a cancer patient, John Moore, sued the University of California. Cancer cells had been removed from Moore as part of his medical treatment; these cells were studied and manipulated by researchers. The resulting cells were "immortalized" and were patented by the university as and have become widely used research tools. The subject of the litigation was the financial gain that the university and researchers achieved by additionally charging money to companies by licensing the cell line.