KRT7 and neuroendocrine carcinoma: An immunohistochemical analysis, albeit limited to a NEC population, has reached similar conclusions to ours, showing that tumors of gastrointestinal origin are predominantly CK7-negative, whereas those of lung origin are CK7-positive (p < 0.0001), and that GEP-NECs are significantly more likely to express somatostatin receptors (p = 0.0021) [44,47].