Bone marrow production of these “classical” monocytes is not CSF-1R-dependent, and although they are precursors of inflammatory macrophages in colitis, they are also precursors of a minor (~10%) population of “nonclassical” monocytes that are Ly6Clo in mice and CD14lo CD16+ in humans and that have increased potential to express TNFα. Here, TNF is linked to colitis.