For example, in osteoporosis and osteonecrosis patients, QEF treatment was shown to elevate the levels of serum matrix metalloproteinase-2, bone ALP, osteocalcin, cross-linked C-telopeptide of type I collagen, and urinary cross-linked N-telopeptide of type I collagen [2, 10]. Here, MMP2 is linked to osteoporosis.