Cre recombinase tool; Aquaporin 5 (AQP5) belongs to a family of water channel proteins that allow water to pass through the plasma membrane by osmosis. AQP5 is expressed in salivary gland and lung epithelial cells. When crossed with a reporter mice, reporter gene expression can be detected in Aqp5 positive cells. When crossed with a strain carrying a gene flanked by loxP sites, the flanked gene will be removed in cells expressing cre.