MTOR and pulmonary arterial hypertension: In light of the KEGG pathway and hallmark gene set, GSEA showed enrichment of genes chiefly involving in MAPK/ERK (MEK), mTOR and Toll‐like receptor signalling pathways (Figure 7B), and all of them was reported to act as an essential regulator in the pathogenesis of PAH; however, MAPK/ERK (MEK) signalling pathway top the list based on Normalized Enrichment Score (NES).