To further validate the expression profiles and oncogenic properties of PIK3CD-L (encoding full-length PI3Kδ) and PIK3CD-S (splice variant missing exon 20, encoding a short splice isoform PI3Kδ-S), a TMA containing AA and EA PCa specimens and a panel of AA and EA PCa cell lines were subjected to IHC and Western blot assays. This evidence concerns the gene PIK3CD and posterior cortical atrophy.