Insulin-like growth factor II mRNA binding protein 3 (IMP3) is an oncofetal RNA-binding protein that regulates targets such as insulin-like growth factor-2 and beta-actin. IMP3 plays a major role in early embryogenesis involving the development of the intestine, thymus, pancreas, and kidneys. IMP3 mRNA transcript and protein have been demonstrated in high levels in pancreatic cancer tissues but not in benign lesions of the pancreas, chronic pancreatitis, or normal pancreatic tissues. IMP3 can be used to distinguish between pancreatic ductal adenocarcinoma from chronic sclerosing pancreatitis. IMP3 expression has also been found in a variety of other human cancers including renal cell carcinoma, adenocarcinoma of the uterine cervix, endometrial carcinoma, adenocarcinoma of the esophagus, malignant melanoma, Merkel cell carcinoma, urothelial carcinoma, neuroendocrine carcinoma of the lung, adenocarcinoma of the pancreas, and triple negative breast cancer.