“…This idea was further developed by Salerno [31,32] who introduced nonhomogeneities in the model and studied the dynamics of DNA promoters in the context. His results have attracted attention [5,12] and other nonlinear excitations [1,34,35], such as discrete breathers, are emerging as important for DNA dynamics and function. These works take advantage of the large amount of research [3,4,13,14,21,23,24] that has been concerned with understanding discrete breathers in nonlinear systems in recent years.…”