Our previous study reported that Smac-mimetic reduced cyst growth in Pkd1 conditional knockout mice (Pkd1flox/flox:Pkhd1-Cre mice) by inducing the cyst-lining epithelial cell apoptosis only, which provides the first evidence that induction of cystic epithelial cell apoptosis is a therapeutic strategy in PKD [67]. The gene discussed is PKHD1; the disease is cyst.