Retraction. PKNOX2 gene is significantly associated with substance dependence in European-origin women.

GENETICS, SOCIAL SCIENCES Retraction for ‘‘PKNOX2 gene is significantly associated with substance dependence in European-origin women,’’ by Xiang Chen, Kelly Cho, Burton H. Singer, and Heping Zhang, which published online August 31, 2009, in Proc Natl Acad Sci USA (10.1073/pnas.0908521106). The authors wish to retract this paper because its publication violates the Gene Environment Association Studies Genes and Environment Initiative Study of Addiction: Genetics and Environment (SAGE) dataset’s embargo policy. The SAGE data access agreement states that investigators agree not to submit findings of the SAGE dataset(s) for publication until September 23, 2009. The authors sincerely apologize for this violation of SAGE policy.