HDAC4 and posterior cortical atrophy: Collectively, our findings suggest that hsa_circ_0003258 functions as a novel positive regulator for PCa metastasis through both hsa_circ_0003258/miR-653-5p/ARHGAP5 axis and hsa_circ_0003258/IGF2BP3/HDAC4 axis (Fig. 9).