PARP1 and glioblastoma: A similar approach was employed using the alpha-emitting radiopharmaceutical astatine-211-labeled MM4 (211At-MM4), which targets poly(ADP-ribose) polymerase 1 (PARP1), to evaluate the combined therapeutic effect of alpha radiation and PD-1 immune checkpoint blockade in a syngeneic mouse model of glioblastoma.