In 27 patients (52%), the EGFR promoter methylation study was conducted on primary colorectal tumours, in 21 cases (40%) both primary tumours and corresponding metastasis (liver metastases in all cases) were available for analysis, while in 4 cases (8%) only the metastatic site (liver metastases in all cases) was investigated. The gene discussed is EGFR; the disease is neoplasm.