To determine the role of USP11 in human skin cancer, we evaluated the protein levels of USP11 by immunohistochemical staining in normal human skin tissue (Normal, n = 21), actinic keratosis (AK, pre-malignant, n = 15), and squamous cell carcinoma (SCC, malignant, n = 16). Here, USP11 is linked to squamous cell carcinoma.