CD34 and Krebs 2 carcinoma: Based on the estimation of numerical density of endothelial cells expressing CD34 in Krebs-2 carcinoma tissue, we suggest that intratumoral injection of the strain NDV/Altai/pigeon/770/2011 indicates that virus is able to directly or indirectly affect neoangiogenesis of the developing tumor, interfere with normal regulation of the nutrient supply to the tumor tissue and result in extensive necrotic lesions.