CD55 and diabetes mellitus: On the other hand, DAF does not lie under any of the reported T1D linkage peaks[23,24] nor have there been any reports of genetic association studies between DAF and autoimmune disease, although recently differential expression of DAF was observed when comparing T cells from nonobese diabetic (NOD) mice and diabetes-resistant NOD mice having a congenic interval containing the DAF gene thereby making it a candidate gene for the Idd5.4 region (William Ridgway and Linda Wicker, unpublished observations).