A method of sensing and removing subclinical, precancerous cells from skin wherein the unblemished skin is not being treated for AK, fine lines or clinical wrinkles and is not chronically exposed to sun or UV radiations, the method comprising topically applying to skin of a patient a composition essentially comprising of an TLR7 agonist agent, Imiquimod in an amount effective to induce a cellular immune response in the skin resulting in the sensing and removal of subclinical, atypical keratinocytes by erythema, scaling, crusting, or combinations thereof.
