Later, this DNA binding protein was identified as HMGA1, and its expression was markedly reduced in two unrelated patients with either the Type A syndrome or the common form of type 2 diabetes, in whom cell surface INSRs were decreased and INSR gene transcription was impaired despite the fact that the INSR genes were normal, thus indicating defects in INSR gene regulation (15, 89, 133). This evidence concerns the gene HMGA1 and type 2 diabetes mellitus.