HIF1A and posterior cortical atrophy: Importantly, endogenous co-immunoprecipitation (co-IP) and cell-free protein pulldown assays revealed that ASH1L-F3 directly interacted with the HIF-1α protein (Fig. 3g and Supplementary Fig. 5e), reinforcing the notion that ASH1L and HIF-1α function as a complex in metastatic PCa cells.