By immunohistochemistry and western blotting, we found that PADI4 and CK have similar distributions in the colon, oesophagus, bladder, lung, rectum, stomach and breast cancer, thyroid tumour, oesophageal squamous cell carcinoma, hepatocellular carcinoma, and other non-adenocarcinomas. The gene discussed is PADI4; the disease is breast carcinoma.