In our prior work, we were able to demonstrate that the combination of quercetin (Q, chemical structure in Figure 1B) with GT significantly increases tissue concentrations of GTPs and decreases the methylation of GTPs into less-active metabolites, leading to an enhanced inhibition of prostate tumor growth in mice, associated with an increased inhibition of several critical signaling pathways involved in prostate cancer, including the androgen receptor (AR) and PI3K/Akt pathways [12]. Here, AR is linked to Familial prostate cancer.