CSF1 and acute kidney injury: It is interesting to note that the deletion of proximal tubule CSF-1 or the blockade of CSF-2 in AKI leads to a reduction in expression of M2 Mφ-specific genes, which appears modest (<30%; except regarding Arg1 expression), which may have resulted from the altered ratio of infiltrating and kidney-resident Mφ, as blood-circulating Mφ are not affected by the deletion of proximal tubule CSF-1 or the blockade of CSF-2 (Huen et al., 2015; Wang et al., 2015).