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). This evidence concerns the gene CCR1 and neoplasm.