ESR1 and osteoporosis: In addition, previous studies have reported that estrogen inhibits VSMCs osteogenic differentiation in vitro and arterial calcification in vivo by promoting autophagy [44], while in postmenopausal women with osteoporosis treated with estrogen, the mRNA expression of estrogen receptor and alkaline phosphatase (ALP) increased, suggesting that estrogen may have a significant effect on osteoblastic differentiation of bone marrow MSCs in women with osteoporosis [45].