KRAS and pancreatic ductal adenocarcinoma: KRAS mutations are especially prevalent in pancreatic ductal adenocarcinoma (PDAC), colorectal cancer (CRC, ~40%), and non-small cell lung cancer (NSCLC, ~30%), with PDAC showing over 90% prevalence of KRAS mutations, predominantly at codon G12 (G12D, G12V, G12R).