Then, we investigated ER levels and ER binding activity in regards to skin cancer initiation, promotion and progression stages (represented by C5N, P1, B9, A5 and CarB cell lines) and we emphasized on the in vitro and in vivo effects of ERα-specific targeting in the aggressive characteristics of CarB by S554fs, a dominant negative mutant of ERα (dnERα). Here, ESR1 is linked to skin neoplasm.