PECAM1 and neoplasm: DC101 was a highly effective anti-angiogenic agent, as shown by the large decrease in CD31 immunostained blood vessels in the CPA and DC101 co-treated tumors (Figure 2B), but caused only a modest tumor growth delay, consistent with the relative insensitivity of 9L tumors to angiogenesis inhibition [38] (also see Figure 3A, below).