UNLABELLED: What's known on the subject? and What does the study add? Inflammation is known to play a role in BPH. Growth factors such as IGF and FGF are also known to play a role in the development of BPH. The paper shows that (1) TGFBR2, a member of the TGF family, has a protein expression related to prostate gland volume, and (2) highlights the interaction between inflammation and TGFBR2 for the development of BPH. OBJECTIVE: *  To assess transforming growth factor β-receptor II (TGFBRII) protein expression in benign prostatic hyperplasia (BPH) using immunohistochemistry analysis, and to compare the analysis with phenotypic properties. METHODS: *  TGFBRII protein expression was profiled using three clinical outcome tissue microarrays (TMAs), sampled from 231 patients who underwent surgery for BPH. *  Using these TMAs, five inflammatory cell markers were also assessed, including CD3, CD4, CD8, CD20, and CD163. *  The surgical procedure was open prostatectomy in 95 patients and transurethral resection of the prostate in 136 patients. RESULTS: *  TGFBRII protein expression was found in BPH epithelium cells for both basal and secretory cells, as well as in fibromuscular stromal cells. TGFBRII staining was also strong in most of the lymphocytes infiltrating the prostate. *  TGFBRII stromal staining was found to be significantly associated with prostate volume (P = 0.04), whereas TGFBRII epithelial staining was found to be significantly associated with 5-α-reductase-inhibitor medical therapy received by patients before surgery (P = 0.004). *  Both stromal and epithelial TGFBRII staining were found to be associated with CD4 T-lymphocyte infiltrate, independently of prostate volume (P < 0.001 and P = 0.002). CONCLUSIONS: *  TGFBRII protein expression in BPH is associated with prostate gland volume and with CD4 T-lymphocyte prostatitis. *  TGFBRII might be a promising therapeutic target to prevent prostate enlargement or even to decrease prostate volume.