Further selection of proteins with a p-value < 0.001 revealed that large ribosomal subunit protein uL4 (RPL4) and beta/gamma crystallin domain-containing protein 2 (CRYBG2) were significantly upregulated, while the unreviewed proteins A0A5C2G728 and A0A7S5C3H4 were significantly downregulated in the OSA+HUA group compared to the OSA group (Fig. 4B). Here, RPL4 is linked to obstructive sleep apnea syndrome.