USP19 and cancer: Consequently, in the following paragraphs, results denoting USP19 relevance in different signaling pathways regulating cell proliferation and cell-cycle progression, as well as tumor growth and metastasis will be presented, therefore unveiling the importance of conducting extensive studies to further the study of USP19’s dual role in tumorigenesis under different molecular scenarios, and to establish its significance as a potential new target for the clinical treatment of cancer.