Family history of ICAs or SAH, which is reported to be risk factors for the complication of ICAs in ADPKD, sex (female), which is a known to be a risk factor for ICAs in the generalized population, and serum MMP1 level were significantly associated with the complication of ICAs in ADPKD in our clinical study (Table 2)44, 45. The gene discussed is MMP1; the disease is autosomal dominant polycystic kidney disease.