PEBP1 and breast cancer: In further support of the notion that CCL5 plays a causal role in RKIP-mediated suppression of breast cancer cell invasion, expression of CCL5 is sufficient to rescue the inhibition of invasion in RKIP expressing 4175 cells while the expression of CCL5 alone had no effect on the invasive capacity of the 4175 cells (Fig. 3d).