PARP1 is an important enzyme participating in several cellular processes such as DNA damage repair, various types of cell death (parthanatos, apoptosis, necroptosis or autophagy), synthetic lethality, regulation of chromatin structure, DNA methylation, regulation of transcription (and thereby the development of an inflammatory process or cell differentiation), and finally carcinogenesis—mainly by regulating transcription of genes encoding proteins involved in cancer progression [11,12,13,14,15,16,17,18,19,20,21,22]. The gene discussed is PARP1; the disease is cancer.