One molecule identified as a key player in these MET-driven processes was Rac1. It is widely understood that Rac1 is involved in cancer cell migration; however, the team found Rac1 to also be critical in driving cancer cell growth, via interaction with another protein called mTOR. This interaction occurs inside the cells (in structures called endosomes), followed by a relocation of the two molecules to the cell boundary—an unusual place for mTOR to be found. In a separate pathway, MET also communicates with another molecule, PI3K, to drive cell migration.