Interestingly for EGFR and KRAS, the most common mutations in NSCLC, the mutation profile of the former fell just between the never and the current (EGFR: 33.2% as former vs. 20.7% as current, P < 0.001; 33.2% as former vs. 67.9% as never, P < 0.001; KRAS: 6.7% as former vs. 11.9% as current, P = 0.041; 6.7% as former vs. 3.3% as never, P = 0.024). Here, KRAS is linked to non-small cell lung carcinoma.