CSF1 and neoplasm: Interestingly, the hypoxia attractants, including colony stimulating factor 1 and 2 (Csf1 and Csf2), and CCl2, were higher in LysM-Cre;Nrp1L/L mice at the end of the experiment; however, the LysM-Cre;Nrp1L/L tumor associated macrophages were mainly found in areas of normoxia and absent in areas of hypoxia (26).