For instance, a previous single-cell RNA study has reported that the infiltration of proinflammatory FABP4 macrophages is detected in lung metastatic osteosarcoma lesions, and TIGIT (T cell immune receptor with immunoglobulin and ITIIM domain) blockade treatment significantly facilitates the cytotoxicity effects of the primary CD3+ T cells with a high proportion of TIGIT + cells against osteosarcoma (Zhou et al., 2020). This evidence concerns the gene TIGIT and osteosarcoma.