PDCD4 and central nervous system cancer: Programmed cell death 4 (PDCD4) is considered a tumor suppressor gene (3) and is frequently down-regulated in several types of cancers, such as lung cancers (4), pancreatic cancers (5), hepatocellular carcinomas (6), colon cancers (7), skin carcinomas (8), invasive ductal breast carcinomas (9), and gliomas (10).