CNR1 and IgA glomerulonephritis: Particularly, CB1 and CB2 have been found to be expressed in a variety of cells in human normal kidney samples [11, 101], and increased expression of CB1 in renal biopsy specimens has been demonstrated in many renal diseases, including IgA nephropathy, acute interstitial nephritis, diabetic nephropathy, obesity-related glomerulopathy, and focal segmental glomerulosclerosis [34, 48].