K-ras gene mutations were not detected in any of the EGFR mutated tumours and this negative correlation was statistically significant (P=0.001), while EGFR gene mutation status did not correlate with p53 gene mutation status or with promoter hypermethylation status of p16, RASSF1A, or APC1A gene (Table 4). The gene discussed is KRAS; the disease is neoplasm.