CD1C and breast cancer: To examine the immune environment of breast cancer at high resolution, we re-clustered immune cells to identify myeloid cells, and we identified 12 clusters of myeloid cells (Supplementary Figure S1A), and in combination with differentially expressed genes in different clusters and classical M1/M2 marker gene expression (Supplementary Figures S1B, C), we annotated five M2-like (LYVE1+, CX3CR1+, SPP1+, FABP5+, and PDE4C+) macrophages, one M1-like (CXCL10+) macrophage, three dendritic cells (CD1C+, XCR1+, and SLCO5A1+), monocytes (Mon), and other cells (Figure 2G).