HLA-DPA1 and neoplasm: Finally, in tumor myeloid cells negative for TREM1 expression, we observed consistently higher expression of MHC class II antigen-presenting genes (HLA-DRA, HLA-DRB1, HLA-DMB, HLA-DPA1, HLA-DQA1) and the Th1-associated chemokine, CXCL9. However, these genes were not observed to be down-regulated by TREM-1 activation in the Dower et al.