As shown in Figure 11, compared to the normal mammary epithelial cells MCF-10A, these prognostic genes exhibit distinct expression patterns in BC cell types, As shown in Figure 11, compared to MCF-10A, the expression levels of RPLP2, PRKAA2, CLIC6, FLT3, CHI3L1, etc., have decreased in most breast cancer (BC) cells, while the expression levels of PCDHGA2 and IYD have been significantly upregulated, especially IYD, which is expressed very little in normal mammary epithelial cells, consistent with our previous single-cell results. Here, CHI3L1 is linked to breast cancer.