SF-1 is a master regulator of steroidogenesis whose expression is critical for normal adrenal and gonadal organogenesis. Strict maintenance of SF-1 levels is essential, and mutations causing under- or overexpression result in congenital adrenal and gonadal defects or hyperplasia, respectively. Data from transgenic mouse models points to a network of transcription factors responsible for stringent regulation of Sf-1 expression during development, which bind to intronic enhancer elements in addition to the basal promoter to specifically modulate transcription in each Sf-1-expressing tissue. Furthermore, analysis of the role of SF-1 in adrenal tumourigenesis implies that improper developmental regulation of Sf-1 expression may have postnatal consequences separate from the well-documented developmental defects.