To evaluate the hypothesis that the previously demonstrated anti-tumor effects of palbociclib on the memory CD8 T-cell pool (13) would be enhanced by co-treatment with SX-682, which has been shown to reduce the recruitment of myeloid-derived suppressor cells (MDSCs) into the TME, we compared the effects of palbociclib alone versus palbociclib in combination with the CXCR1/2 antagonist SX-682 on the tumor growth of B16-F10 melanoma in C57BL/6 mice. The gene discussed is CXCR1; the disease is melanoma.