Siglec‐7 and Siglec‐9 ligands were readily detected on both the TN tumor cell lines (HCC1143, HCC1937, MDA‐MB‐231, MDA‐MB‐468) and the ER+ tumor cell lines (BT‐474, MCF7, MDA‐MB‐175, T47D) (Figure 4a and Supplementary figure 5). Here, SIGLEC9 is linked to neoplasm.