CRLF3 and plexiform neurofibroma: The human CRLF3 gene was first identified (as cytokine receptor-related molecule 4 or CYTOR4) in the context of neurofibromatosis type 1 (NF1), a disease characterized by benign nerve tumors called neurofibromas in concert with melanocyte and skeletal defects, as well as cancer susceptibility [58].