While we did not detect a separate hillock cell population within our prostate cancer epithelial cells (Supplementary Fig. 1e), we did detect a distinct population representing 6.5% of all epithelial cells (872 of 13,322) characterized by expression of PIGR, MMP7, CP, and LTF (Fig. 2d) (FDR q < 10e-20). This evidence concerns the gene PIGR and Familial prostate cancer.