Papillary variants express platelet derived growth factor receptor (PDGFR-α)- alpha and dipeptidyl peptidase-4 (DPP4) as markers, whereas reticular cells express PDGFR-α, delta-like noncanonical Notch ligand 1(DLK1) and spinocerebellar ataxia type 1 (SCA1) [42]. This evidence concerns the gene DPP4 and spinocerebellar ataxia type 1.