Moreover, SPP1 mRNA levels were significantly higher in BM compared with other metastatic sites (liver, lymph nodes, lung and other), in the GSE74685 (Fig. 1B) and SU2C-PCF [32] datasets (Fig. 1C), suggesting that the BME participates in the regulation of SPP1 expression in PCa cells. Here, SPP1 is linked to posterior cortical atrophy.