TP53 and posterior cortical atrophy: Since we have reported the rapid P53-Ser15P by PGG treatment in LNCaP PCa cells [7] and have observed P53-Ser15P in PGG-exposed MCF-7 cells (Figure 1b) and since the P53-P21Cip1 axis is best known for mediating G1 arrest by genotoxic stress [19], we focused on the relationship among these proteins in PGG-exposed MCF-7 cells.