KRAS drives 1 in 7 of all human cancers. 90% of the KRAS driven cancers are caused by 9 different KRAS mutants. It took 36 years to bring drugs against the first KRAS mutant KRASG12C to Phase 1 clinical trials after Channing Der’s discovery in 1982 that KRAS is an oncogene. It will be discussed why it took so long for medicinal chemists to discover drugs against the first KRAS mutant and BI’s learnings from internal efforts against KRAS. Importantly, it will be highlighted what this means for the future practice of medicinal chemistry (MedChem2.0). The talk will also highlight a selection of the multiple approaches that Boehringer-Ingelheim is taking to drug KRAS including pan-KRAS concepts and selective KRAS concepts. The importance of not only inhibiting MAPK pathway signaling but also blocking negative feedback will be emphasized. The practice of MedChem2.0 will be needed to drug the many KRAS mutants yet to be drugged in order to bring medicines to patients with KRAS driven cancers and RASopathies.