For instance, diffuse loss of nuclear menin (protein encoded by MEN1) immunostaining in multifocal pulmonary neuroendocrine (micro)tumors or thymic neuroendocrine tumors should alert diagnosticians to the possibility of MEN1 syndrome even in the absence of a family history [88] (Fig. 4). This evidence concerns the gene MEN1 and multiple endocrine neoplasia type 1.