Therapeutic targeting of RAS: New hope for drugging the "undruggable".

RAS is the most frequently mutated oncogene in cancer and a critical driver of oncogenesis. Therapeutic targeting of RAS has been a goal of cancer research for more than 30 years due to its essential role in tumor formation and maintenance. Yet the quest to inhibit this challenging foe has been elusive. Although once considered "undruggable", the struggle to directly inhibit RAS has seen recent success with the development of pharmacological agents that specifically target the KRAS(G12C) mutant protein, which include the first direct RAS inhibitor to gain entry to clinical trials. However, the limited applicability of these inhibitors to G12C-mutant tumors demands further efforts to identify more broadly efficacious RAS inhibitors. Understanding allosteric influences on RAS may open new avenues to inhibit RAS. Here, we provide a brief overview of RAS biology and biochemistry, discuss the allosteric regulation of RAS, and summarize the various approaches to develop RAS inhibitors.