Here, we demonstrate that anti-Gal-9 therapy in combination with ATM inhibition synergically suppresses tumor growth and prolongs survival in three syngeneic mouse models, including colon tumor and the poorly-immunogenic LLC lung tumor which generally lacks TILs and is unresponsive to anti-PD-1/PD-L1 therapy 37. Here, LGALS9 is linked to neoplasm.