The NEN component of MiNEN primarily exhibited high proliferation rates with more than 20% Ki67-positive tumor cells (91.7%, 11 out of 12 cases) and were classified as NET G3 (N = 2), small-cell carcinoma (SCNEC; N = 3) or large-cell carcinoma (LCNEC, N = 6), according to histomorphology and immunohistochemical analysis (Table 3). This evidence concerns the gene MKI67 and neoplasm.