Follicular thyroid adenoma and carcinoma [147], primary and metastatic neuroendocrine tumours [148,149,150], NK cell lymphomas [150], malignant plasma cell dyscrasias, especially multiple myeloma [145]; and alveolar rhabdomyosarcoma [151] represent just few examples of CD56-positive differential diagnoses. Here, NCAM1 is linked to neuroendocrine neoplasm.