Additionally, several studies have reported that prostate cancer cells express the Wnt inhibitor Dickkopf-1 (DKK-1) [43], and since Wnt regulates osteoblastic differentiation, the hyperexpression of DKK-1 results in the inhibition of osteoblastogenesis processes, further promoting the growth of prostate cancer cells within the bone marrow [44] (Figure 1). This evidence concerns the gene DKK1 and Familial prostate cancer.