The recent description of a lupus-like disease in normal mice after injections of human mAb that bind DNA and carry the common Id 16/6 Id has excited much attention. In an effort to reproduce this model we have performed two experiments using eight human mAb three of which bear the 16/6 Id. Despite using an injection protocol very similar to that of the original authors and waiting for up to 1 yr we were unable to detect any autoantibodies or any evidence of renal disease. We suspect that our failure to reproduce the model may be due to differences in either or both the batches of CFA used, or in the animal house environments. It supports the view that a mosaic of effects is required to induce clinical expression of an autoimmune disease.