When examining the difference in expression between all cases of primary colorectal cancer and lymph node metastasis CYP7B1 (p=0.035), CYP39A1 (p=0.001), CYP46A1 (p<0.001) and CYP51A1 (p<0.001) each showed a significant decrease in immunoreactivity in lymph node metastasis compared to primary tumour. The gene discussed is CYP7B1; the disease is colorectal cancer.