CSF1 and neoplasm: Macropinocytosis can be induced in macrophages by stimuli other than CSF1, including lipopolysaccharide (LPS) (Zanoni et al., 2011), the chemokine CXCL12 (Lou et al., 2014) and the tumor promoter phorbol 12-myristate 13-acetate (PMA) (Swanson, 1989).