KRAS and non-small cell lung carcinoma: In M2, top ranked keywords are used most in clinics to diagnose and treat tumor diseases; The histo-technical terms to detect tumor genes from tumor cell and tissue, such as “nano gram”, “EGFR”, “IHC”, and “KRAS”, tumor related keywords (“tumor”, “NSCLC” and “tumor DNA”), and treatment keywords (“therapy”, and “targeted therapy”) are grouped together.