CD6 and pulmonary arterial hypertension: In view of the DEGs enrichment analyses results presented earlier that DEGs in the PAH samples were mostly enriched in immune‐related response, genes in cluster 2 (BCL2L1, CCR7, CD5, CD6, CD19, CD40LG, IL7R and LCK) related to immune modulation were selected and then verified with KEGG pathway enrichment analysis in STRING.