SMAD4 and ameloblastic carcinoma: MAPK8IP2 gene encodes a scaffold protein: The JNK-interacting protein (JIP), that is more abundantly expressed in the cerebellum, pituitary gland, occipital lobes and the amygdala, and it could be associated to Ameloblastic Carcinoma and Spinocerebellar Ataxia X-Linked 5.