The subgroup analysis by PSA levels showed that all of those men had higher PSA levels: of the eleven men with higher PSA levels treated with onabotulinumtoxinA, three had a PVR urine volume of ≥ 200 mL (two of three men had urinary tract infection) and four had an AE of urinary retention. The gene discussed is KLK3; the disease is urinary tract infection.