Konukiewitz et al. [9] reported that abnormal nuclear p53 and Rb1 staining was found in 29/37 and 22/37 poorly differentiated neuroendocrine neoplasms, respectively, whereas all well-differentiated neuroendocrine neoplasms showed normal p53 and Rb1 expression. Here, RB1 is linked to neuroendocrine neoplasm.