POU5F1 and prostate adenocarcinoma: We have shown the rather surprising result that many of the cells of the glands of “well-differentiated” adenocarcinoma of the prostate express six antigens, CD133, LGR5, CD44, ALDH7A1, NANOG and Oct4, antigens that have been shown to be “stem cell” markers in a variety of systems as discussed further below.