Root epidermis development in Arabidopsis provides a simple and powerful model for studying cell fate specification. Cellular, molecular, and genetic approaches have been used to define many genes, and their corresponding proteins, that are essential for the position-dependent specification of the two root epidermal cell types. These studies have led to a working model in which a network of transcriptional regulators that is influenced by positional cues establishes differences in gene expression in neighboring cells through a set of positive and negative feedback loops. The continued analysis of this experimental system is likely to provide new insights into mechanisms of transcriptional regulation and cell–cell interactions during development.