The frequency of smokers ≥30 pack-years (50.0%, 4/8) and smokers 0–30 pack-years (25.0%, 2/8) among patients with tumours having KRAS mutations was significantly higher than that among smokers 0 pack-years (6.5%, 5/77) (P=0.002) (Table 2). Here, KRAS is linked to neoplasm.