In the United States, about 600,0001 people have PKD, and cystic disease is the fourth leading cause of kidney failure. Autosomal dominant PKD is the most common inherited form. Symptoms usually develop between the ages of 30 and 40, but they can begin earlier, even in childhood.
In developmental biology, cellular differentiation is the process where a cell changes from one cell type to another. Most commonly this is a less specialized type becoming a more specialized type, such as during cell growth. Differentiation occurs numerous times during the development of a multicellular organism as it changes from a simple zygote to a complex system of tissues and cell types.
separation. 1  an act or instance of separating or the state of being separated. 2  a place, line, or point of parting. 3  a gap, hole, rent, or the like. 4  something that separates or divides. 5  Law. cessation of conjugal cohabitation, as by mutual consent. 6  Aerospace. the time or act of releasing a burned-out stage of a rocket or missile from the remainder.