312 Female sex independently predicts adjuvant immunotherapeutic benefit from CTLA4 immune checkpoint inhibition by Gary Cohen, Omid Hamid, Lawrence Flaherty, Henry Koon, Jeffrey Sosman, David Minor, Zeynep Eroglu, John Kirkwood, F Stephen Hodi, Donald Lawrence, Ni Kang, Sandra Lee, Laura Hutchins, Harriett Kluger, Kari Kendra, Carrie Lee, Mark Albertini, Teresa Petrella, Howard Striecher, Vernon Sondak