CDK8 and posterior cortical atrophy: The effects of CDK8/19i on the expression of PSA, the principal biomarker of PCa, were validated at the protein level by measurement of secreted PSA in the conditioned media from LNCaP and several other PCa cell lines (C4-2, LN3, VCaP, 22Rv1) treated with different concentrations of CDK8/19i Senexin B, SNX631, Senexin C (25), and 15w (60) (Supplemental Figure 8, B–D).