In this system, where LILRB3 is present only on the hematopoietic cells, and predominantly monocytes, in the absence of appreciable numbers of neutrophils, ligation of LILRB3 with an agonistic LILRB3 mAb before injection of allogeneic lymphoma cells (36, 37) induced tolerance in vivo and enabled subsequent tumor cell engraftment. Here, LILRB3 is linked to lymphoma.