CD44 and neoplasm: In the rectal cancer model, SPP1+ macrophages and FAP+ fibroblasts co-locate within the tumor, where they contribute to the formation of connective tissue and prevent the invasion of the tumor core by T cells or B cells [18].And the LGALS9-CD44/CD45 inhibitory signal displayed by macrophages may inhibit the activation of T and B lymphocytes that are spatially adjacent to macrophages [28].