CREB1 and gastric neuroendocrine tumor, well differentiated, low or intermediate grade: M-GNET is closely related to clear cell sarcoma of soft tissue (CCSST), sharing highly overlapping morphological features and molecular genetic characteristics, particularly <i>EWSR1-ATF1</i> gene fusion and, more rarely, <i>EWSR1-CREB1</i> gene fusion.