AR and prostate cancer: In addition, sGCα1 protein is over-expressed in both AR-expressing prostate cancer cells and prostate tumors, while sGCβ1 is weakly expressed [13], showing that there is a significant pool of endogenous sGCα1 that is free of sGCβ1 and therefore it is possible that Peptide B-8R targets this sGCα1 protein.