LGALS9 and neoplasm: The main mechanisms of interaction between tumor cells and tumour-associated macrophages are LGALS9-SLC1A5, CCR1_CCL23, CSF1R _CSF1, GRN_SORT1, CSF1_SIRPA, and SIRPA_CD47, which primarily induce macrophage differentiation to M2 type while inhibiting macrophage phagocytosis of tumor cells, cause immune escape, and promote tumor cell proliferation, invasion, and metastasis (31–35).