The KRAS gene is mutated in one-third of tumors and its importance in promoting the growth of cancer cells has been known for decades. However, efforts to develop a KRAS inhibitor have so far been unsuccessful. Now, researchers may have found a way to suppress KRAS indirectly using a drug called deltarasin. To function properly, KRAS needs to be attached to the cell's membrane, a process aided by the transport protein PDE-δ. Deltarasin blocks PDE-δ, preventing KRAS from anchoring to the cell membrane. A recent study showed that deltarasin reduced the growth of KRAS-mutant tumor cells both in cell culture and in a mouse model of pancreatic cancer.