FKBP4 and Familial prostate cancer: FKBP51 and FKBP52 might be linked to the etiology of prostate cancer, given that the levels of FKBP51 and FKBP52 have been found to be elevated in human prostate cancer, compared to the noncancerous part of the prostate gland [36, 37, 38, 39].