FSHR and cancer: The target validation for FSHR proved challenging for three reasons: (i) numerous publications about cancer cell lines or tissues expressing hFSHR did not specify the exact antibody used for analyses; (ii) a number of purchased antibodies could either only be used for certain applications (e.g., ELISA), did not recognize cell-presented hFSHR, or were unspecific [26]; and (iii) the antibodies used in two studies [10,11] for IHC detection of FSHR in the tumor cells of prostate adenocarcinomas are no longer available.