CSF3 and neutropenia: It has been suggested that the presence of increased G-CSF values and numbers of granulocyte-macrophage colony-forming cells (GM-CFCs), along with the simultaneous presence of neutropenia in burn and burn-infected animals is due to other immune alterations resulting from burn injury, including reduced G-CFC responsiveness to G-CSF, altered cell-cycle of GM-CFCs by increased levels of PGE2, and a shift from granulocytopoiesis to monocytopoiesis, rather than an impairment in endogenous G-CSF levels.