Fig. 2. In mammals, aquaporin isoforms are often organised into subfamilies. Humans have paralogs from tandem duplications, resulting in four extra AQP7 pseudogenes and a second copy of AQP12. The majority of them have a distinct tissue-specific expression pattern. Most mammalian AQPs may be dynamically controlled, making them prospective targets for the development of novel therapies to treat disorders related with water homeostasis disruptions.