Gene expression analysis of skin biopsies of patients with AK and BCC after topical treatment with imiquimod has shown that the TLR7 agonist induces the expression of a large number of interferon inducible genes indicating the importance of type 1 interferons in the mechanism of resolution of pre cancerous and cancerous skin lesions [22-24]. Here, TLR7 is linked to skin basal cell carcinoma.