The pursuit of effective cancer treatments is not only fraught with scientific complexities, but also legal complications. Biotech company Genentech is suing Penn for patent fraud on a cancer treatment that both entities believe to be theirs. At Penn, the treatment was tested on transgenic mice who were engineered to have cancer. When a patent from biotech company Genentech came to Penn’s attention, they claimed Genentech was infringing on their patent. Genentech filed a complaint in May 2010 and is now suing for patent fraud.