IL21R and benign prostatic hyperplasia: In recent years, our laboratory observed the changes of N-cadherin, E-cadherin, and vimentin triggered by RNA interference on BMP5, SMO, and interleukin 21 receptor (IL-21R), accompanied by the proliferation/apoptosis imbalance, fibrosis alterations and reactive oxygen species changes in mesenchymal and epithelial cells [22,40,47], which provided strong evidence for the involvement of EMT in the development of BPH.