KITLG and neurofibroma: Other factors or receptors, such as hepatocyte growth factor and its receptor c-MET [84,85], platelet-derived growth factor [86], TGF-β [87], insulin-like growth factor 1 receptor [88], midkine [89], lysophosphatidic acid [90], and stem cell factor and its receptor c-Kit [91], have also been reported to participate in the development of both neurofibromas and MPNSTs.