PKD1 and kidney disorder: Pigs have similar renal physiology and structure to humans, with a multipapillary kidney, rather than the unipapillary structure of rodents, and, therefore, represent an excellent kidney disease model (Figure 1).74 Unfortunately, the one currently available ADPKD model, a PKD1+/− miniature pig model, has slowly progressive PKD with cysts forming at 5 months of age and the kidney structure only beginning to change at 24 months, with some liver cysts (Table 1).74,75 Similar to humans and rodents, PKD1−/− pigs are lethal.