Subsequent experiments established that CUX1 knockdown is synthetic lethal in all cancer cells exhibiting high levels of ROS due to an activating mutation in a RAS gene (Hs578THRAS, MDA-MB-231KRAS, DLD-1KRAS, HCT116KRAS, KE37NRAS), another gene in the pathway (HT29BRAF), or an upstream receptor tyrosine kinase (HCC827EGFR) ([9,38] and Ramdzan et al., in preparation). Here, CUX1 is linked to cancer.