CCR5 and neoplasm: Since most of the phenotypic changes in the tumor-infiltrating leukocytes occurred in the polymorphonucleate subset that is also the most prominent population in the 4T1 model, we assessed the effect of Ly6G+cell depletion in 4T1 bearing mice undergoing 4PD treatment with shRNAs specific for CCR1 and CCR5 or scrambled shRNAs as control (figure 4C).