In addition, the expressions of PI3K mRNA, Akt mRNA, and NF-κB p65 mRNA were downregulated (Figure 6C), indicating that d-limonene can inhibit the activation of the PI3K/Akt/IKK-α/NF-κB p65 signaling pathway in PF rats. The gene discussed is CHUK; the disease is pemphigus foliaceus.