MYC and posterior cortical atrophy: Since the MYC pathway, a major driver of advanced PCa, was one of the pathways selectively downregulated by MKI in 22Rv1 xenografts growing in castrated mice, we asked whether CDK8/19i treatment would affect the growth of MYC-CaP-CR (58), a derivative of the MYC-driven transgenic PCa model MYC-CaP (59) selected for the ability to grow in castrated mice.