Thus, incidence of EGFR mutations was lower in poorly differentiated tumours than in well-differentiated tumours (34.2 vs 72.0%, P=0.005, odds ratio: 4.9, 95% confidence intervals: 1.5–15.9) or than in moderately differentiated tumours (34.2 vs 64.4%, P=0.008, odds ratio: 3.5, 95% confidence intervals: 1.3–9.2) (Table 4). Here, EGFR is linked to neoplasm.