PARP9 and neoplasm: Another class characterized by strong binding to ADP-ribosylated proteins without catalytic activity is the MacroH2A-type clade, which include the epigenetic tumour suppressor MacroH2A18,19, and the macrodomains from multidomain human PARP9, PARP14, and PARP15, which are involved in the regulation of cell migration associated with lymphoma (PARP9 and PARP14)20, in tumour suppression (PARP15)21 and in the host-virus response (PARP14 and PARP15)22.