Positive DNMT1 staining was seen in 57.6% of patients carrying the wild type but 96.2% of the patients with the mutated KRAS. Positive staining for DNMT1 but negative staining for DNMT3a was most frequent in NSCLC patients when the KRAS mutational status was ignored. Here, DNMT3A is linked to non-small cell lung carcinoma.