NCAM1 and small cell lung carcinoma: Eichhorn et al. reported that simultaneous expression of both NCAM and chromogranin A was associated with poor outcome and high risk of recurrence in LCNEC patients.18 Hamanaka et al. reported that a subset of SCLC with low neuroendocrine expression showed better prognosis than a subset with high neuroendocrine expression.19 However, neither of them explained why neuroendocrine expression was correlated with malignancy.