CYP24A1 and diabetic kidney disease: Indeed, analysis of the key players in the metabolism of vitamin D during diabetic nephropathy progression shows that CYP24A1 expression is significantly increased in the proximal tubules of db/db (C57BL/6 Lpr −/−) mice versus db/m+ (C57BL/6 Lpr −/m+) mice, as well as in animals fed a high fat diet for 8 weeks.