NKX2-5 and coronary artery disorder: The relative size of the C-set within the total mutant target set (C-set/B-set ratio) correlates with the location and predicted severity of NKX2-5 mutations (∆HD>Y191C≥ YRDY−A), and thus B-set and C-set size and content may prove to be valuable signatures for understanding the relationship between genotype, phenotype, and clinical outcomes in CHD.