Finally, to determine whether ferritin can induce cyst growth and whether CPX is dependent on iron to slow cyst growth, ADPKD cells were grown in 3D culture to form cysts, followed by treatment with CPX-O, holoferritin (ferritin with iron), apoferritin (ferritin without iron), or a combination. Here, FTH1 is linked to autosomal dominant polycystic kidney disease.