333 Targeting the apical intracellular checkpoint CISH unleashes T cell neoantigen reactivity and effector program by Matthew Johnson, Ying Hu, Nicholas Restifo, Jared Gartner, Douglas Palmer, Shashank Patel, Maria Parkhurst, Todd Prickett, Parisa Malekzadeh, David McKenna, Zulmarie Franco, Suman Vodnala, Beau Webber, Yogin Patel, Christine Kariya, Walker Lahr, Rigel Kishton, Devikala Gurusamy, Miechaleen Diers, Natalie Wolf, Nicholas Slipek, Darin Sumstad, Lydia Viney, Tom Henley, Tilmann Bürckstümmer, Oliver Baker, Chunhua Yan, Daoud Meerzaman, Kartik Padhan, Winnie Lo, Li Jia, Drew Deniger, R Scott McIvor, Modassir Choudhry, Branden Moriarity