Evidence check: MC4R in the context of Langlebigkeit

MC4R (melanocortin-4 receptor) is a key regulator of energy balance and appetite. Mutations in MC4R are the most common monogenic cause of early-onset obesity. Some studies suggest that certain MC4R variants are associated with increased BMI, which can indirectly affect lifespan. However, there are no robust GWAS or longevity studies directly linking MC4R to extended or shortened lifespan. The effects are moderate and strongly modifiable by lifestyle factors. Relying solely on MC4R variants to predict longevity is not evidence-based. Instead, focus on diet, exercise, and metabolic health. Note: The provided context does not contain specific data on MC4R.