The HLA important in IDDM is -.: (A) HLA-A3, (B) HLA-B27, (C) HLA-DR3/DR4, (D) HLA-W1
Answer is C. 95% of IDDM (Type I Diabetes Mellitus) patients express either HLA DR3 or HLA DR4 or the heterozygous DR3 / DR4 configuration. 
No HLA association is seen with Type II Diabetes mellitus or NIDDM.