PADI4 expression was detected by immunohistochemistry in all malignant tumor types examined including breast carcinomas, lung adenocarcinomas, hepatocellular carcinomas, esophageal squamous cancer cells, colorectal adenocarcinomas, renal cancer cells, ovarian adenocarcinomas, endometrial carcinomas, uterine adenocarcinomas, bladder carcinomas, chondromas, and other metastatic carcinomas (IRS ≥ 9). Here, PADI4 is linked to metastatic carcinoma.