GCA and type 1 diabetes mellitus: The associated SNP (rs1990760) is embedded in a 236 kb linkage disequilibrium (LD) block on Chr 2q24.3 that includes four genes: IFIH1, also known as helicard or MDA-5 (melanoma differentiation associated gene-5); GCA (grancalcin); FAP (fibroblast activation protein α subunit) and KCNH7 (potassium voltage gated channel subfamily H7), any of which could harbor a T1D-associated functional variant.