HLA C2 alleles, which are ligands for 2DS1 and 2DL1, are underrepresented in T1D, whereas C1 alleles, which are ligands for 2DL2, 2DL3 and 2DS2 (weak interaction), are overrepresented.4 Data from the current study were consistent with that report; C2 was undertransmitted (frequency transmitted =0.291, frequency not transmitted=0.336) to affected individuals, whereas C1 was overtransmitted (f-trans 0.709, f-not trans=0.66; P=0.000139) (data not shown). Here, C2 is linked to type 1 diabetes mellitus.