Furthermore, expression of the forkhead transcription factor FOXO1 is induced with decidualization, both in vivo and in vitro [4], and levels of the tumor suppressor protein p53 and the tetraspanin KAI1 (CD82), a cell surface protein that functions as a metastasis suppressor in tumor cells, are increased posttranscriptionally in decidualized cells [5-7]. This evidence concerns the gene CD82 and neoplasm.