S100A9 and pterygium: After analysis using the online analysis tool Venn, 14 genes (IRAK1, LEF1, CTSS, HLADPA1, S100A8, ARHGDIB, CD59, TAP2, ICAM1, IL4R, CEACAM1, BAX, IL1R1, S100A9) that were up-regulated in both pterygium and pSS samples were screened out, while no DEGs were commonly down-regulated (Figure 3).