KRAS and adenocarcinoma: In lung cancer patients, KRAS mutations have been associated with Caucasian ethnicity (Caucasian vs. Asian population: 26% vs. 11%), female sex (female vs. males: 31.35 vs. 23.7%, p < 0.0001), adenocarcinoma histology (adenocarcinoma vs. squamous cell carcinoma: 37.2% vs. 4.4%), and a positive smoking history (smokers vs. non-smokers: 30% vs. 11%) [26,28].