AXL and neoplasm: This was measured by an increase whole-lung Inos transcript levels, a marker of M1 activation and a decrease in M2 activation markers Arg1 and Fizz1. Contradictory to these studies, inhibition of Axl with a monoclonal antibody has been shown to decrease M1-associated inflammatory factors IL-6, TNF-α and G-CSF production by tumor associated macrophages in MDA-MB-231 xenograft breast cancer models, suggesting Axl promotes M1 polarization some cases [70].