catalytic activity:NAD(+) + (ADP-D-ribosyl)(n)-acceptor = nicotinamide + (ADP-D-ribosyl)(n+1)-acceptor.,miscellaneous:Overexpressed at significantly higher levels in fatal high-risk diffuse large B-cell lymphomas (DLB-CL) compared to cured low-risk tumors. Overexpression in B-cell lymphoma transfectants may promote malignant B-cell migration.,similarity:Contains 1 PARP catalytic domain.,similarity:Contains 2 Macro domains.,subunit:Interacts with BBAP.,tissue specificity:Expressed in lymphocyte-rich tissues, spleen, lymph nodes, peripheral blood lymphocytes and colonic mucosa. Also expressed in nonhematopoietic tissues such as heart and skeletal muscle. Isoform 2 is the predominant form.,