P345: AN IMMUNE SCREEN IDENTIFIES 5-NONLOXYTRYPTAMINE AS A NOVEL ANTI-CANCER AGENT CAPABLE OF IMPROVING ANTI-TUMOR IMMUNITY IN COMBINATION WITH ANTI-PD1 THERAPY. (23rd June 2022) - Stachura, P.; Liu, W.; Wlodarczyk, A.; Xu, C.; Bhatia, S.; Lang, P. A.; Borkhardt, A.; Pandyra, A. A.