Although the C-terminal region of CCR2A does not appear to promote the membrane localization of the receptor, membrane-localized CCR2A is still able to transduce chemokine stimulation to G proteins, and the lack of GRK-target residues makes CCR2A resistant to β-arrestin-mediated internalization, resulting in relatively stronger CCR2A-mediated signals compared with those mediated by CCR2B, suggesting the importance of CCR2A in cancer cell behaviors and progression. Here, GZMK is linked to cancer.