PARP1 and neoplasm: Preclinically, administration of a small peptide‐blocking MZF1‐AS1‐PARP1 interaction or lentivirus‐mediated short hairpin RNA (shRNA) targeting MZF1‐AS1 significantly suppresses the proline synthesis, tumorigenesis, and aggressiveness, indicating the crucial roles of MZF1‐AS1/PARP1/E2F1 axis in tumor progression.