Embryonic cardiac TnT with more negative charges in the N-terminal region and a lower isoelectric point can improve the Ca2+ sensitivity of cTn in an environment with low Ca2+ concentration and increase the force of muscle contraction, compared with the adult isoform of cTnT.77, 78, 79 Thus, in the context of development or cardiac disease, cardiac troponin undergoes functional adaptations by isoform switches to respond to an altered cardiac demand. This evidence concerns the gene TNNT2 and heart disorder.