Abstract
Some specialized animal cells can overtly change from one differentiated phenotype to another through the process of transdifferentiation. In this review article, representative and convincing examples of transdifferentiation in cells of various animals ranging from mammals to coelenterates are presented. Several basic nature of the cellular properties that underly the transdifferentiation process is discussed. Studies are in progress to understand the mechanism of transdifferentiation in terms of gene expression.