CXCR2 and ovarian cancer: We thank Dr. Ann Richmond (Vanderbilt University, Nashville, TN, USA) for CXCR2 expression vector, Dr. Xiao-Fan Wang for p21 promoter (Duke University, Durham, NC, USA), Dr. Andrew Godwin (University of Kansas Medical Center, Kansas City, KS, USA) for providing A2780 human ovarian cancer cell line, Dr. Joseph Testa (Fox Chase Cancer Center, Philadelphia, PA, USA) for Akt1 expression vector, and Dr. Julia Shao for the assistance in flow cytometry analysis (Meharry Medical College, Nashville, TN, USA).