CD4 and neoplasm: As expected, LLC tumors grown in FIH+/+ mice have foci of infiltrating inflammatory cells including F4/80-positive macrophages, FOXP3-positive regulatory T cells (Treg), CD4 and CD8 T cells (an example of LLC tumor grown in FIH+/+ is shown in SI Appendix, Fig. S3A), confirming that the syngeneic LLC subcutaneous tumor model is suitable for studying the role of FIH on TME and tumorigenesis.