The mitochondrial and cytoplasmic superoxide anion imbalance trigger the expression of certain cellular aging markers in HaCaT keratinocytes.

In cells, the term "cellular aging" represents a collection of biological changes that can precede the proliferative senescence states. Cells more resistant to proliferative senescence, such as the ones found in the basal layer of the epidermis, may also exhibit these aging patterns. Therefore, cellular aging events could be induced by endogenous signals named here as cellular aging triggers (CATs) components.