Interstitial monocytic infiltration of the kidney occurs within hours of acute kidney injury and is an important determinant of functional decline and fibrosis. Li et al. used several surface markers to distinguish between dendritic cells and inflammatory monocytes following acute kidney injury and to identify two chemokine receptors that regulate monocyte traffic. This Commentary examines the degree to which monocyte-lineage diversity, trafficking, and contribution to renal injury have been teased out to date.