NOS2 and type 2 diabetes mellitus: T2D stimulates the production of iNOS-derived NO, which increases PPARγ production by HSC and, therefore, stimulates differentiation of HSC to osteoclasts; in addition, iNOS-derived NO increases the activities of cathepsin K and collagenase and osteoclast activity (Percival et al., 1999[116]; Gyurko et al., 2005[51]; Alselami et al., 2015[6]).