Importantly, miR-1 expression correlates inversely with overproduced growth hormone and IGF-1, as well as dramatically increased cardiac myocyte size in cardiac biopsies of patients with acromegaly, demonstrating the clinical relevance of a feedback loop between miR-1 expression and the IGF-1 signal transduction pathway in human cardiac hypertrophy [22]. This evidence concerns the gene IGF1 and acromegaly.