Interestingly, an ongoing clinical trial is evaluating gefitinib in human CD patients with USP8 mutations, but no results have been released so far (Targeted therapy with gefitinib in patients with USP8-mutated Cushing’s disease; ClinicalTrials.gov (accessed on 13 February 2024), identifier: NCT02484755). This evidence concerns the gene USP8 and Cowden disease.