SIGLEC9 and cancer: The majority of human TAMs constitutively express Siglec‐9,[45] and the signaling function of Siglec‐9 and Siglec‐E, the murine ortholog of Siglec‐9, was reported to suppress the phagocytosis of macrophage cells both in vitro and in vivo.[12, 46] Therefore, we hypothesized that the trans interaction of DSG2 on cancer cells with Siglec‐9 on TAM might constitute a “don't eat me” signal and suppress phagocytosis.[47]