EPHB4 and neoplasm: Interestingly, these appeared to function differently: mAb131 recognized only human EphB4 on the tumor cells, and caused receptor endocytosis and degradation; whereas mAb47, recognizing also mouse EphB4, severely blocked blood vessel perfusion in tumors, and was also active against tumors in which the tumor cells did not express EphB4, consistent with targeting the TME.