MMP1 and familial isolated congenital asplenia: In our study, vascular cells from ADPKD-iPSCs showed impaired intracellular Ca2+ homeostasis, which may result from a PKD1 or PKD2 mutation, compared with those from control-iPSCs, but no significant differences were observed between vascular cells from ADPKD patients with and without ICAs, in spite of the differences in the expression of some genes, including MMP1. These results suggest that other genetic modifiers besides PKD1 and PKD2 are associated with the development of ICAs in ADPKD.