Tumor suppressor genes make proteins that help control cell growth. Mutations in these genes that generate nonfunctional proteins can contribute to tumor development and progression. One of the most well-known tumor suppressor genes is BRACA1, mutations in which are linked to breast cancer. Researchers have now identified SCARA5 as a candidate tumor suppressor gene in human hepatocellular carcinoma, a form of liver cancer that is the fifth most common cancer worldwide