HBA2 and obstructive sleep apnea syndrome: The expression levels of the top ten upregulated (EIF1AY, USP9Y, UTY, ERAP2, IMPAD1, PPBP, HBA2, HBB, TM4SF19, EGFL6) and downregulated (PKGD1L1, LINC00917, IL6, MIR21, DUSP1, CD69, PTGS2, FOS, FOSB, EGR1) genes in OSA are shown in the heatmap in Figure 1B.