on no noted increase in the cancer-associated Ki67 marker, (3) improve specific multiple manifestations of aging skin, (4) thickens the epidermis without the irritation, dryness, or inflammation associated with retinols, and (5) is effective in a variety of skin types. These observations support the mechanism of action hypothesis that defensins activate the body’s own skin stem cells to generate healthy new epidermal cells. The defensins specifically stimulate young and “preserved” LGR6-positive stem cells.10 These skin’s master stem cells (“master“ because these give rise to the entire lineage of the epidermal cells)8,9 accumulate less mutations and damage than actively proliferating basal stem cells due to their quiescent status and “safe” residence in the isthmus, which is not as directly exposed to UV radiation as basal stem cells.20 By activating