Although most studies highlighted the beneficial effect of periodontal treatment on the reduction of PSA levels, Kruck et al. (2017) showed that supra- and infra-gingival biofilm debridement alongside adequate instruction in oral hygiene techniques was not enough to significantly reduce PSA levels, probably due to the limited number of PSA measurements and the prostatitis classification of the selected patients [38]. The gene discussed is KLK3; the disease is prostatitis.