Using a public database of single cell RNA sequencing performed on 8 breast tumors ((36), http://panmyeloid.cancer-pku.cn/), we observed that CMKLR1 is mainly expressed in a macrophage subpopulation with a high expression of CD14, CD163 and HLA-DRA, and with a low expression of CD80 and CD86. Additionally, expression of CMKLR1 was not observed in macrophage subpopulations expressing high levels of HLA-DRA, CD80 and CD86 (Figure S9A). Here, CD14 is linked to breast neoplasm.