KLF5 and posterior cortical atrophy: Our findings of Ac-KLF5 being essential for the mesenchymal phenotype (Figs. 2e and 3l, and Supplementary Figs. 2 and 4), tumorigenicity (Fig. 3), bone metastatic lesions (Fig. 2), and chemoresistance (Fig. 8 and Supplementary Fig. 9) establish KLF5 acetylation as a mechanism through which PCa cells change to survive stresses (i.e., by becoming mesenchymal and slowly proliferating).