The ability of selective HDAC1 inhibitors to restore SLFN11 expression in some resistant cancer cell lines (29) and the subset of prostate cancers in the TCGA data with low SLFN11 expression despite low promoter methylation suggested a potential epigenetic mechanism by which CD47 signaling could alter SLFN11 expression in prostate cancer. This evidence concerns the gene CD47 and Familial prostate cancer.