Imiquimod is a topical immune response modulator which acts through the toll-like-receptor 7 pathway. It is FDA approved for the treatment actinic keratosis, genital warts, and superficial basal cell carcinomas. It has also been used off-label for the treatment of squamous cell carcinomas in situ and invasive cutaneous squamous cell carcinomas. A review of published studies to date found 50-88% clearance rate for squamous cell carcinomas in situ treated with daily application of topical imiquimod. There is only one study, other than case reports of treating invasive squamous cell carcinomas with topical imiquimod. In that study, 7 out of 12 (71%) invasive squamous cell carcinomas cleared with topical imiquimod 5 days per week for 12 weeks. Common reported adverse reactions are erythema, pruritus, weeping, erosions, crusting at the application site.