The relationship has been previously reported between poly(ADP-ribosyl)ation and CD31 and VEGF expression in vascular smooth muscle cells (VSMCs) [31,32], such as facilitation of DNA repair by prolonged poly(ADP-ribosyl)ation in VSMCs, and the direct effect of PARP inhibitor on tumor vascularization through changes in CD31 expression levels was reported in in vivo models of anaplastic thyroid carcinoma. This evidence concerns the gene PECAM1 and thyroid gland undifferentiated (anaplastic) carcinoma.