HLA-C and autoimmune thyroid disease: Rose made many other key observations in thyroid autoimmunity, including the first understanding of the importance of both major histocompatibility complex (MHC) and non-MHC genes in determining susceptibility, the crucial additional role of environmental factors, and the description of autoreactive T cells in normal, healthy individuals, implying the need for active suppressive mechanisms to prevent autoimmunity arising.