HSPB6 and Familial prostate cancer: As a supplementary experiment, we supplemented 200 μM 8-Br-cGMP after overexpressing HSPB6. The results showed that although 200 μM 8-Br-cGMP did not significantly induce apoptosis in prostate cancer cells alone, it significantly increased the apoptosis of HSPB6-induced prostate cancer cells (Supplementary Fig. 3E, F).