RPGRIP1L−/− mutant organoids treated with 5 μM hydroxyfasudil and 2.5 μM fasudil had significantly fewer cysts (p = 0.01059 and p = 0.03711, respectively; Fig. 6c), whereas cyst number remained unchanged for control organoids treated with ROCK inhibitors or 8-Br-cAMP. This evidence concerns the gene RPGRIP1L and cyst.