Given the importance of KSR1 in modulating signaling through the Raf/MEK/ERK kinase cascade in tumor cells and observations thatksr1–/– mice develop with only inconsequential phenotypic differences, targeting KSR1 or KSR1-dependent signaling pathways in Ras-driven cancers may selectively target cancer cells with reduced toxicity to patients. Here, KSR1 is linked to cancer.