We, for the first time, found that EGFR levels are statistically significantly higher in normal colorectal mucosa biopsy samples than they are in colorectal carcinoma biopsy samples, the median EGFR levels being 77.5 fmol mg-1 of membrane protein (range 35-239), against 46 fmol mg-1 of membrane protein (range 22-81), respectively, P less than 0.001. The gene discussed is EGFR; the disease is colorectal carcinoma.