TIPARP and neoplasm: However, a recent study analysed the effect of PARP7 knockout in EO771 mouse mammary cancer cells and in a preclinical syngenic tumour model, utilizing wild-type and catalytically inactive mutant Parp7H532A mice, and showed that loss of PARP7 function modestly reduced cancer cell proliferation, while not affecting tumour growth in immunodeficient mice.