Compared with the BPH group, the KQR and finasteride groups had decreased mRNA expression levels of TGF-β, TGF-βR1, Smad2, and N-cadherin and increased expression mRNA expression levels of BAMBI and E-cadherin (P<0.05 or P<0.01). Here, SMAD2 is linked to benign prostatic hyperplasia.