The expression of the H2-Aa (corresponding to HLA-DQA), H2-Ab1 (HLA-DQB1), H2-DMa (HLA-DMA), H2-DMb (HLA-DMB), H2-Eb (HLA-DR), H2-Oa (HLA-DOA), and H2-Ob (HLA-DOB) genes decreased stepwise as the severity of infection worsened, and the H2 genes were expressed mainly in B cells rather than in myeloid cells (Appendix Fig. S10). This evidence concerns the gene HLA-DQA1 and infection.