PARP7-IN-22 (XLY-1) is a PARP7 inhibitor with an IC 50 of 0.6 nM. PARP7-IN-22 (XLY-1) is orally active, enhances type I interferon signaling in vitro, restores type I interferon signaling, promotes T cell infiltration into tumor tissues, and significantly inhibits tumor growth. PARP7-IN-22 shows promise for research in the field of cancer immunotherapy.