COL4A4 and Renal cyst: Finally, it is important to note that the KDIGO (Kidney Disease Improving Global Outcomes) 2025 ADPKD Guidelines indicate that pathogenic variants in the collagen genes COL4A3, COL4A4, and COL4A5 may be associated with mild phenotypes of type IV collagen-related disease, in which renal cysts can be observed.