The generation of Patz1-knockout mice [16] and the characterization of their phenotype by our group confirmed the tumor suppressor hypothesis since a significant number of both heterozygous and homozygous Patz1-knockout mice developed neoplastic lesions, including lymphomas, hepatocellular carcinomas, and rare sarcomas and lung adenocarcinomas (Figure 3) [39]. The gene discussed is PATZ1; the disease is neoplasm.