CCR4 and cancer: However, we did not observe a ZEB1-dependent effect on proliferation of CD8 + T cells in vitro when co-cultured with BMDMs, but a ZEB1-dependent modulation of CD8 + T cell migration by CCL2 and CCL22, as discussed above, as well as CCR2 and CCR4 expression in CD8 + T cell subsets in murine and human cancers.