Exome sequencing of patients with clinically suspected ADPKD but no pathogenic PKD1 or PKD2 variant identified, which can account for up to as many as 15% of patients with multiple kidney cysts, has now identified more than 13 cystogenic genes (i.e., ALG8, ALG9, DNAJB11, GANAB, HNF1B, IFT140, SEC61B, PKHD1, PRKCSH, SEC63, COL4A3/4/5) that account for up to half of these initially genetically unresolved ADPKD cases.17 The gene discussed is ALG9; the disease is autosomal dominant polycystic kidney disease.