RUNX2 and osteoporosis: Previous studies have found that the mutations of genes such as those for CSF1 (macrophage colony stimulating factor 1) [2] and FTH1 (ferritin, heavy polypeptide 1) [3], and osteoporosis-related genes such as COL1A1 (collagen, type1, alpha 1) [4], LRP5 (low-density lipoprotein receptor-related protein 5) [4], RUNX2 (runt related transcription factor 2) [5], WNT3A (wingless-related MMTV integration site 3A) [6], DKK1 (abstract dickkopf-1) [6], and RANKL (receptor activator of NF-kB ligand) [7] are related to primary osteoporosis.