Overall, these findings provide the basis for designing a prospective study in ADPKD patients aimed to document the efficacy of sirolimus treatment in preventing further increase or even reducing the total kidney volume and the renal volume taken up by small cysts, eventually halting kidney disease progression. It is a 6 month treatment with sirolimus compared to conventional therapy in adult patients with ADPKD and normal renal function or mild to moderate renal insufficiency.