Abstract: A vertebrate, non-human transgenic animal whose cells, both somatic and germinal, contain a recombinant genetic construction formed of a marker gene and a regulator region capable of being induced in the epidermis of said transgenic animal in response to hyperproliferative stimuli, the genetic construction of which has been introduced into the animal or into an antecessor of the animal in an embryonic stage. The genetic construction is induced also in the bulb of the hair in the phase of active growth or anagen. The said genetic construction consists of a marker gene characterized by the fact that it is easily detectable, under the control of the regulator region of the gene of the K6 keratin, this protein being characterized by its ability to be induced in the suprabasal layers of the epidermis in response to hyperproliferative stimuli both endogenous (tumors, cicatrization of wounds, diseases which, such as psoriasis, produce hyperproliferation, etc.