CLCF1 and osteoporosis: Our study provides clinical evidence demonstrating that the CLCF1 gene expression level in PBMCs may reflect BMD in elderly women, especially the role of the CLCF1 protein level in indicating BMD of the lumbar spine, femoral neck, greater trochanter, and Ward’s triangle, all of which are the most likely skeletal sites of osteoporosis and fracture [17].