It was 100% positive for epithelial marker pan-cytokeratin (panCK), 40% positive for special AT-rich sequence-binding protein 2 (SATB2), 10% positive for neural cell adhesion molecule (CD56) and 100% positive for Synaptophysin (Figure 2A–D) characterizing the colorectal tumor as large cell GEP-NEC according to the WHO-classification of 2010. Here, NCAM1 is linked to neuroendocrine carcinoma.