C5AR2 and neoplasm: C5AR2 was mainly expressed on macrophages, e.g. Kuffer cells, and mesenchymal cells, e.g. Ito cells in the HPA database (https://www.proteinatlas.org/ENSG00000134830-C5AR2/celltype), then the abundance of these two immune cells infiltrating in the tumor microenvironment may be indirectly reflected by C5AR2 expression levels.