FGD4 and Familial prostate cancer: Additionally, we performed TCGA database analysis of FGD4 copy number alteration and mRNA expression in prostate cancer using Trento/Cornell/Broad 2016 [37] and TCGA provisional datasets [38] (Fig. 1d), which revealed an increased FGD4 DNA copy number in 19% of the cases with neuroendocrine prostate cancer and mRNA upregulation in 4% of the cases with PCA (Fig. 1d).