Immunohistochemicalanalysis of FKBP51 in human cancers.

FKBP51 is a FK506-binding immunophilin involved in the regulation of several fundamental biological processes. A growing body of data indicates that this protein has also a role in the abnormal cell growth of cancers, and could be considered as a promising new marker of tumor progression and response to radio/chemotherapy. However, the data concerning the expression of FKBP51 in cancer are not conclusive, and partially contradictory. They delineate a very complex scenario, in which many molecular FKBP51-related pathways are variously intersected among different tumors. This review reports the available data concerning FKBP51 expression in normal tissues and human malignancies, outlining the role of the immunohistochemical analysis as a fundamental tool for better understanding the role of this immunophilin in cancer biology.