The cells of the body are perfectly capable of making proteins with a life span of many months, still the cells make proteins which are short-lived. On one hand, they make proteins like hemoglobin having a life span of approximately 120 days, and on the other hand, it makes proteins with life span of few days, such as a tumor suppressor protein. The short lived proteins have their own advantage, as they allow the cells to control their function, and amount precisely.