There is recent evidence to suggest that an autoimmune mechanism may be associated with the gastric mucosal changes found in pernicious anaemia. Markson and Moore (1962) and Irvine et al. (1962) found a complement-fixing antibody to gastric mucosa in the blood of 42% and 75% respectively of their patients with pernicious anaemia; and Taylor et al. (1962), using an immunofluorescent technique, demonstrated an organ-specific autoantibody in 85% of 100 patients. These last workers also showed that the antigen was localized in the cytoplasm of the parietal cells, and was recoverable in the " microsomal " fraction of homogenized gastric mucosa. The autoantibody to gastric parietal cells was shown to be quite distinct from the antibody to intrinsic factor first described by Taylor (1959