PSPN and posterior cortical atrophy: Figure 7 provides a model of the transition in cell phenotype that we envision occurring as a consequence of PSPN cleavage by MMP-7. Notably, chronic activation of FOXM1 is a hallmark of metastatic cells [35], and FOXM1 was found to be highly active in aggressive but not indolent PCa cells including CTCs [9].