BGN expression is increased in many cancers including bladder cancer [39], colorectal cancer [42], gastric cancer [43], esophageal cancer [44], prostate cancer [40], and endometrial cancer [45] and various factors modulate its expression, including p38 [46], HIF-1 [47], TGF-β/Smad4 [48], and NF-κB [26]. Here, SMAD4 is linked to prostate cancer.