123 Assessing cytotoxic T cell responses in live tumor fragments (LTF)™ with multiphoton microscopy oleh Chao Liu, Ellen Wargowski, Evan Flietner, Michael Korrer, Debra Bloom, Christin Johnson, Jonathan Oliner, Jason Tt. Smith, Jonathan N Ouellette, Anna Kellner, Max Shiller, Lauren Nettenstrom, Zac Swider, Janey Degnan, Matt Conklin, Lindsay Doebert, Eric Wait, John Rafter, Christopher D Zahm