CCR2 and neoplasm: Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins (2019 Dec 12 -)) and advanced renal cell carcinoma (ClinicalTrials.gov [Internet]. Bristol-Myers Squibb (2017 Feb 2 – 2021 Nov 23)), where both trials use anti-PD-1 concurrently. CCR2+ MDSCs are found within the tumor microenvironment of glioblastomas (Takacs et al. (2021)), making CCR2 inhibition a desirable therapeutic mechanism for exploration.