CNR1 and diabetes mellitus: Since EPO is generated by interstitial fibroblast in close proximity to the RTPCs [33,34] as well as by tubular cells [32], and the fact that the eCB system affects RPTC’s function via modulating the activity of CB1R [19,20,22], it was only natural for us to further investigate the involvement of RPTC-CB1R in influencing bone impairment during diabetes via affecting EPO levels.