NF1 and neoplasm: The NF1 tumor suppressor gene encodes the cytoplasmic protein neurofibromin that acts as a RAS-specific GTPase-activating protein (GAP) and promotes the conversion of the active guanosine triphosphate (RAS-GTP) form to the inactive guanosine diphosphate (RAS-GDP) form, thereby downregulating its biological activity (Bos et al., 2007; Cherfils and Zeghouf, 2013; Scheffzek et al., 1997).