According to Gini score calculated from gene expression values, we examined the top-6 most important AA metabolism-related genes (including PLA2G6, PLA2G7, AKR1C1, AKR1C3, LTA4H, and PTGER4) in sarcoidosis, whose expression showed a positive correlation with sarcoidosis samples (Fig. 5k). The gene discussed is PTGER4; the disease is sarcoidosis.