ABCG4 and posterior cortical atrophy: Transcription levels of eight ABC transporter genes, including ABCA8, ABCB1, ABCC6, ABCC9, ABCC10, ABCD2, ABCG2, and ABCG4, were significantly down-regulated in PCa, and only two genes, ABCC4 and ABCG1, were up-regulated.