AR and posterior cortical atrophy: More than 20 different ARVs that have been identified in clinical PCa tissues and PCa cell lines and among these variants, AR-v7, originates from contiguous splicing of AR exon 1, exon 2, and exon 3 with the cryptic exon 3 (CE3) present within the canonical intron 3 of the AR gene. It is one of the most well characterized ARVs and can be reliably measured in tissue and liquid biopsy specimens, and blood-based detection [35–38].