During aging, many physiological functions gradually deteriorate, such as wound repair. Surprisingly, our recent study revealed that the stem cell number is not significantly reduced in aged skin, but becomes functionally exhausted. Based on these findings, the third research direction we have established in my laboratory is to continue employing our in utero microinjection technique to build innovative tools and sophisticated models to investigate questions such as what factors trigger stem cell exhaustion, how stem cells become exhausted, and why stem cell exhaustion leads to delayed wound repair. Interestingly, while we have found that chronic inflammation can induce “epigenetic scars” and temper the capacity of stem cells to sense and adapt to the inflammatory environment in the wound, the transformed stem cells can overcome these changes. So, another direction of the lab is to explore how oncogenic signals allow cancer stem cells to not only overcome chronic inflammation-induced exhaustion, but even enhance the immune evasive capacity of cancer stem cells