APOE and infection: However, PMNs infiltrating the brain of Rag1–/– mice exhibited a mix of proinflammatory (LCN2, APOE) and antiinflammatory (WFDC21, RETNLG) molecules that was most prominent at day 7 after infection along with enhanced PD-1/PD-L1 pathway expression (Supplemental Figure 10D).