RAS proteins function as on/off switches in pathways controlling cell growth and proliferation. Mutated RASs keep the pathways permanently activated, leading to conditions such as cancer and Noonan syndrome. A protein called Leucine Zipper-like Transcription Regulator 1 (LZTR1) regulates cellular levels of RAS by promoting RAS’s destruction. However, LTZR1 is itself prone to mutations, disrupting its ability to bind and degrade RAS and causing diseases such as Noonan syndrome and Schwannomatosis.