HOXA7 and cardiomyopathy: Toward a potential function in sarcomerogenesis, one gene whose down-regulation caught our attention is the Mlc2 gene as its mutation was shown to cause flight muscle sarcomeric phenotypes highly similar to Antp KD (41) and recessive mutations of its vertebrate homolog, MYL2, were associated with infantile muscle fiber disease and cardiomyopathy, displaying similar sarcomeric phenotypes [(42); reviewed in (43)].