PIP5K1A and posterior cortical atrophy: Since ISA‐2011B is a selective inhibitor of PIP5K1α, a key regulator that acts upstream of PI3K/AKT to promote proliferation and survival of PCa cells [21], we therefore used ISA‐2011B alone or in combination with tamoxifen to assess the effect of tamoxifen on PIP5K1α/PI3K/AKT pathways in PCa cells (Fig. 1C).