BMAL1 and sarcopenia: In terms of gross phenotype, mice lacking Bmal1 display decreased body size and weight [16, 17], as well as abnormal knee joint morphology and calcified tendons [18], indicating that the growth and development of these animals can be greatly affected by Bmal1. In addition to impaired growth, Bmal1 global knockout also leads to significantly lower survival rates in mice [17] and display several signs of premature aging, including sarcopenia, cataracts, subcutaneous fat loss, and organ atrophy [16].