Although disulfiram combined with copper does not reduce tumor size, it increases PD-L1 expression and blocks T-cell entry by inhibiting PARP1 activity and enhancing Glycogen synthase kinase 3 phosphorylation at Ser9 via the (poly (ADP-ribose) polymerase family, member 1) PARP1 gene [223]. The gene discussed is PARP1; the disease is neoplasm.