Contrary to BCCs, in a number of more biologically aggressive carcinomas—including breast, lung, colon, prostate, pancreas, and thyroid cancers—as well as in some benign lesions such as benign prostatic hyperplasia, “recruitment” of CD34-immunoreactive fibroblasts into tumor stroma occurs [27,28,29,30,31,32,33]. Here, CD34 is linked to benign prostatic hyperplasia.