(From EurekAlert). Scientists have made more progress in understanding the mechanisms of cell aging. "Aging cells are called senescent cells [and are] no longer able to divide but remain metabolically active. Accumulation of senescent cells over time appears to contribute to changes in tissue form and function commonly associated with aging, like the skin changes that occur between childhood and old age. ... Most importantly, the failure of cells to stop growing through differentiation or senescence can lead to the uncontrolled growth of cancer." This work identifies more of the biochemical mechanisms that control senescence; further investigation "might allow rationale design of therapeutics to treat cancer patients and even alleviate some aspects of human aging."