The specificity of this monoclonal antibody to its intended target was validated by HuProtTM Array, containing more than 19,000, full-length human proteins. The intestine-specific transcription factors CDX1 and CDX2 are important for directing intestinal development, differentiation, proliferation and maintenance of the intestinal phenotype. CDX2 protein expression has been seen in GI carcinomas. Anti-CDX2 has been useful to establish GI origin of metastatic adenocarcinomas and carcinoids and is especially useful to distinguish metastatic colorectal adenocarcinoma from lung adenocarcinoma. However, mucinous carcinomas of the ovary also express CDX2 protein. It limits the usefulness of this marker in the distinction of metastatic colorectal adenocarcinoma from mucinous carcinoma of the ovary.