Estrogen receptor expression in human tumors: A tissue microarray study evaluating more than 18,000 tumors from 149 different entities.

Estrogen receptor (ER) is a ligand-activated transcription factor with a critical role in development and function of multiple organ systems and a well-established drug target for breast cancer. To comprehensively evaluate ER expression in normal and tumor tissues, a tissue microarray containing 18,560 samples from 149 different tumor types and subtypes and 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry (IHC). ER positivity was found in 55 different tumor types including 26 entities with at least one strongly positive tumor.

Brachyury expression is highly specific for chordoma: A tissue microarray study involving 14,976 cancers from 135 different tumor types and subtypes.

Brachyury protein plays a role in defining the midline of bilaterian organisms. Commonly expressed in chordomas, brachyury immunohistochemistry is used to distinguish chordomas from their differential diagnoses. However, brachyury expression has also been described to frequently occur in other cancer entities.

Correction: High prevalence of p16 staining in malignant tumors.

[This corrects the article DOI: 10.1371/journal.pone.

Carcinoembryonic Antigen Expression in Human Tumors: A Tissue Microarray Study on 13,725 Tumors.

Background/objectives: Carcinoembryonic antigen (CEA) is a cell-surface glycoprotein serving as a drug target, diagnostic marker, and serum marker for cancer monitoring. However, prevalence data on CEA expression in cancer tissues vary considerably. This study was designed to determine CEA expression in normal and neoplastic tissues.

Prevalence and clinical significance of Claudin-3 expression in cancer: a tissue microarray study on 14,966 tumor samples.

Background: Claudin-3 (CLDN3) participates in the formation of the tight-junctions (TJs) that regulate intercellular permeability. Altered CLDN3 expression has been linked to tumor progression in multiple tumor types. Despite its widespread expression in normal epithelial cells, CLDN3 is considered an attractive drug target candidate, since it may be more accessible in cancer cells than in normal cells due to their less orchestrated cell growth.