CCR1 and cancer: On the other hand, it has been reported recently that MSCs secret CCL5, which is critical for maintaining the MSCs identity and multi-potency.29 In addition, CCL5/CCR1 axis is pivotal for the communication between MSCs and their target tissues.30, 31 Altogether, these findings make us to hypothesize that CCL5 may play a role in mediating a synergistic crosstalk between MSCs and cancer cells to sustain CRC growth and metastasis.