Immunoblot analysis further showed that expression of MMP9, a key regulator of extracellular matrixes in PCa invasion (Sarwar et al., 2016), was significantly down-regulated in the membrane/cytoplasmic compartments of PIP5K1αΔN cells compared with that of SG controls (for SG cells, mean cytoplasmic MMP9 = 2.23, 95% CI: 1.89-2.57; for PIP5K1αΔN cells, mean cytoplasmic MMP9 = 1.57, difference = 0.66, 95% CI: 1.46-1.68, p = 0.0019, Figures 6B,E). This evidence concerns the gene MMP9 and posterior cortical atrophy.