Kinase suppressor of Ras (KSR; EC 2.7.11.25) is a MAPK scaffold that is subject to allosteric regulation through dimerization with RAF. While deregulation of the Ras-mitogen activated protein kinase (MAPK) pathway is an early event in many different cancers and a key driver of resistance to targeted therapies, direct targeting of KSR could have important therapeutic implications for cancer. However, due to its status as a pseudokinase and role as a non-catalytic regulator of core signalling enzymes, pharmacological approaches that target KSR have been lacking. This is in contrast to current drug discovery and development efforts that have focused extensively on direct inhibitors of the Ras effector kinases RAF, MEK, and ERK[1].