Since both PC1-p30 and PC1-p15 are overexpressed in ADPKD, and since PC1-p30 is known to activate signaling pathways involved in cyst growth, it is reasonable to assume that these proteolytic fragments may play important roles in the mechanisms underlying cyst formation and/or cyst growth in ADPKD. The gene discussed is PKD1; the disease is autosomal dominant polycystic kidney disease.