Abstract The goal of this research is to identify the mechanisms by which eccrine glands are formed with the ultimate aim of regenerating eccrine glands in damaged human skin or in vitro generated skin grafts. We have developed a transgenic mouse line that allows inducible expression of En1 in the epidermis and have shown that induction of En1 during a narrow time window surrounding the initiation of cutaneous appendage development in the region between the footpads of a newborn mouse is sufficient to achieve a complete homeotic conversion of cutaneous appendages, normally hair follicles in this region, to eccrine sweat glands. We will exploit this mouse to identify the genetic pathways that specify eccrine gland development instead of hair follicle formation from a common epidermal placode. The effects of forced En1 expression on inductive signaling from the dermis and on gene expression in the epidermis before and after placode induction will be characterized. ChIPmentation will be used to identify the subset of these genes that are directly regulated by En1 and proximal mediators of this effect. The outcome of this research will include the identification of the genetic pathways that specify the distinctive developmental path of the eccrine gland placode and the dermal signals that initiate this process. The approach also tests two alternative models of En1 action. If one of these alternatives is supported, it will be a paradigm-shifting outcome that emphasizes the role of the epidermis in appendage fate choice. If the other is supported, it will nonetheless advance the field by helping to identify the unique components of the inductive signal from the dermis that drive EG development.