Genetic SP-D variation, altered local protein expression, and serum variation have been reported in extrapulmonary diseases involving autoimmune disorders [including rheumatoid disease (213, 423–426) and diabetes (229, 427)] and in diseases involving specific organs [including the intestines (230, 428), skin (20), brain (41), and large arteries (214, 429)]. This evidence concerns the gene SFTPD and diabetes mellitus.