In human breast cancer cell line MB-231 tumor-bearing mice, the combination of PARP inhibitor and EZH2 inhibitor or the simultaneous knockdown of PARP and EZH2 promoted the polarization of tumor-associated macrophages (TAMs) toward M2 and the generation of neovascularization in tumors (Yang et al., 2020). The gene discussed is PARP1; the disease is breast cancer.