Although this technique would require the isolation of microcells containing only HACs/MACs, the retro-MMCT method could be used to deliver HACs/MACs carrying huge DNA inserts, such as the DMD gene locus or multiple gene expression units, for gene therapy of Duchenne muscular dystrophy and in vivo direct reprogramming, respectively. The gene discussed is DMD; the disease is Duchenne muscular dystrophy.