CYP27B1 and interstitial nephritis: CYP24A1 and CYP27B1 expression in the tubules is elevated in CKD patients with acute renal inflammation, ie, renal vasculitis or interstitial nephritis,42 and in adenine‐treated uremic rats with marked interstitial fibrosis, severe tubular dilatation, microcystic change, and foci of tubular atrophy.37