HLA-DQA1 and acute respiratory distress syndrome: Notably, four MHC complex genes (HLA-DMA, HLA-DMB, HLA-DQA1 and HLA-DRB3), important for antigen-presenting function, as well as genes associated with monocyte adhesion and extravasation (SELL18), transendothelial migration (CD9919) and LPS signaling (MAP2K420) and MAP3K1421) were significantly downregulated in ARDS monocytes (Fig. 1l).