The Ras inhibitor farnesylthiosalicylic acid (Salirasib) disrupts the spatiotemporal localization of active Ras: a potential treatment for cancer.

Chronic activation of Ras proteins by mutational activation or by growth factor stimulation is a common occurrence in many human cancers and was shown to induce and be required for tumor growth. Even if additional genetic defects are present, "correction" of the Ras defect has been shown to reverse Ras-dependent tumorigenesis. One way to block Ras protein activity is by interfering with their spatiotemporal localization in cellular membranes or in membrane microdomains, a prerequisite for Ras signaling and biological activity.