PDCD4 was considered to encode a nuclear antigen and located on chromosome 10. The expression of PDCD4 is regulated by interleukins IL-2, IL-12, and IL-15. The PDCD4 acts as a tumor-suppressor gene and performs essential functions in many biological events, including apoptosis, protein translation, signal transduction, and stimulation of inflammation mediators. The expression of PDCD4 is tightly regulated at the level of transcription, translation, and protein degradation. The loss of expression of PDCD4 is diagnostic indicator for different human cancers, and is prognostic indicator for survival in cancers of the breast, liver, colon, lung, glioma, and esophagus.