ALDH1A1 and posterior cortical atrophy: To further examine the critical roles of bone marrow cells in mediating bone metastasis and to gain deeper understanding of the biological consequences of the interactions between PCa cells and bone marrow cells during the establishment of PCa metastasis in the bone marrow in in vivo conditions, we utilized a PC-3M metastatic mouse model bearing bone metastasis from the intra-cardiac implantation of a subpopulation with a high level of aldehyde dehydrogenase 1 (ALDH1) isolated from PC-3M cells, which were described in our previous studies [22].