In this study, through examination of tumor samples from patients relapsed for the treatment of ketoconazole and dutasteride, we have discovered a novel nonsense mutation Q784* at AR LBD (exon 6), which represents a distinct class of AR mutations that produces a partially LBD-truncated AR protein that structurally and functionally mimics certain LBD-truncated AR splice variants. This evidence concerns the gene AR and neoplasm.