Since then , other genes with a significant role in bone metabolism such as estradiol receptor , collagen type 1alpha1 , TGF beta 1 , interleukin 6 , calcitonin receptor , alpha 2 HS glycoprotein , osteocalcin , calcium sensing receptor , interleukin 1 receptor antagonist , beta 3 adrenergic receptor , apolipoprotein E , PTH , IGF 1 and glucocorticoid receptor have been analyzed . ^^^