APOE and neoplasm: We further found that CXCL16 was highly expressed in Macro_APOE/CTSZ (Fig. 3J) and CXCR6 was expressed in Treg (Fig. 3K), which might indicate that Macro_APOE/CTSZ utilized CXCL16 signals to recruit Treg cells to the tumor site, further exacerbating the immunosuppressive TME.