SIRT6 and colitis: SIRT6 knockout (SIRT6 KO) mice develop acute loss of subcutaneous fat, spontaneous colitis, hypoglycemia, osteopenia, and muscle atrophy at approximately 3 weeks of age, succumbing to death by 4 weeks; therefore, they are useful as a premature aging research model (Li et al., 2020; Mostoslavsky et al., 2006).