Gαq expression within hematopoietic-derived cells is a major determinant of metastatic potential. Lethally irradiated, wild-type, C57Bl/6 mice received transplants of bone marrow derived from either Gαq^+/+ or Gαq^–/– mice. After recovery of hematopoietic function, the mice were intravenously injected with LLC^GFP cells. Shown is the total number of surface pulmonary foci observed within individual transplant recipients (•) as well as the number of foci observed in 4 wild-type mice that had not undergone the transplantation procedure () injected in parallel with LLC^GFP cells. The horizontal bars represent median values. *P < .001, Mann-Whitney U test.