Figure 7.

Model of cyst formation in the adult kidney. Although PKD1-KO at a certain time point (t; x-axis) increases the probability (P; y axis) of cystogenesis, cystogenesis is rare. Even when the adult kidney is challenged by renal injury, which further increases the probability, cyst formation occurs only incidentally (low-frequency cyst formation). However, the initial cysts impose continuous stress onto surrounding tissue, which locally increases the probability and frequency of new cyst formation, leading to a snowball effect (high-frequency cyst formation). As time proceeds, larger regions of the kidney become increasingly susceptible to cyst formation, which ultimately leads to severe PKD.