<qa>  What is another type of antibody that prevents the growth of blood vessels that feed the tumor?Subjects with recurrent GBM and who have currently progressed on Avastin Cohort C, will continue receiving Avastin in combination with MEDI4736. Avastin is another type of antibody that prevents the growth of blood vessels that feed the tumor. Despite Avastin being approved by the FDA for cancer based on tumor response, essentially all patients eventually progress due to resistance. 