Immunohistochemical staining of PC tissues showed that the expression of anti-apoptotic gene Bcl-2 markedly increased in PC tissues compared with BPH tissues, and that high Bcl-2 expression was significantly associated with high Gleason grade (P = 0.02; ICCC = 0.93, κ = 0.88) (Fig. 4a, Additional file 8: Figure S5A). Here, BCL2 is linked to benign prostatic hyperplasia.