ARX and neoplasm: While the α-like and intermediate PanNET include mainly non functioning tumours, the β-like include, as expected, insulinomas.8 Despite enrichment of DAXX/ATRX mutant tumours, high grade and large tumour size in the α like group, ARX and PDX1 expression per se are not able to stratify patients with different risk of relapse.6 8 Indeed, the authors showed that ARX and PDX1 expression was equally distributed in primary tumours and metastasis.6 Therefore, rather than prognostic markers ARX and PDX1 may instead indicate the tumour cell of origin.