Based on this result, a possible scenario in ADPKD kidneys is when a second hit occurs and results in a homozygous PKD1-null cell, its secreted EVs/exosomes may lower the levels of PKD1 in the neighboring PKD1 heterozygous renal cells and then both of these cells contribute to the focal cyst formation. This evidence concerns the gene PKD1 and autosomal dominant polycystic kidney disease.