In addition to Ras signaling, ERK1/2 also receive signals from sprout homolog 2 (SPRY2)/protein phosphatase 2A (PP2A) and Ras-related protein 2B (Rap2B)/focal adhesion kinase (FAK) and activates Runt-related transcription factor 2 (RUNX2) or ETS/AP1 which are essential for PCa/osteocyte interactions [72,104,105,106,107]. Here, RUNX2 is linked to posterior cortical atrophy.