NKX2-5 and coronary artery disorder: Previous interaction researches using electrophoretic mobility shift analysis presented that the DNA-binding T-BOX domain of TBX5 is critical for interaction with NKX2.5 and GATA4 whereas the other regions are not.19 Schott et al. and Ghosh et al. argued that the most of the mutations in TBX5 gene are affective in DNA binding, protein-protein interactions and transcriptional activity.20,21 Other related researches also showed the important role of TBX5 in various types of CHDs.22 To date more than one hundred mutations in this gene have been recognized from patients with CHD.23