Scientists uncover new way to target a mutant protein that causes the deadliest of cancers A new way to target a mutant protein which can cause the deadliest of cancers in humans has been uncovered by scientists at the University of Leeds. The mutated form of the RAS protein has been referred to as the "Death Star" because of its ability to resist treatments and is found in 96% of pancreatic cancers and 54% of colorectal cancers. RAS is a protein important for health but in its mutated form it can be switched on for longer, leading to the growth of tumors.