PDX1 and neoplasm: Recently, chromatin immunoprecipitation DNA-sequencing on H3K27ac super enhancer derived profiles, highlighted that PanNETs fall into two major subtypes, with epigenomes and transcriptomes that partially resemble islet α-cells and β-cells.7 The α-subtype is identifiable by ARX expression and the β subtype by PDX-1 expression; occasionally tumours may expressed both or none of the transcription factors.