Notably, disruption of BMAL1 also promotes heterotopic calcification of tendons and ligaments with aging via activation of TGF/BMP signaling.137 The functional and structural similarities between AF and tendons/ligaments suggest the critical role of BMAL1 in preventing calcification of ligamentous and fibrocartilaginous tissues. The gene discussed is BMAL1; the disease is atrial fibrillation.