SUFU is a key negative regulator in the vertebrate Hedgehog signaling pathway. SUFU interacts with genes encoding proteins in this signal transduction pathway. In Drosophila, Intracellular transduction of the Hedgehog pathway involves the release of a large complex containing SUFU. SUFU inhibits the activity of the transcription factor Gli1 and interacts with Gli2, Gli3 and the serine/threonine kinase Fused. SUFU is widely expressed in adult and embryonic tissues with higher expression in tissues patterned by hegdehog signaling. The SUFU gene locus maps to a region that is deleted in glioblastomas, prostate cancer, malignant melanoma and endometrial cancer.