Other studies have found that quercetin can achieve therapeutic effects on PF by regulating the release of various inflammatory mediators in the NF-κB signaling pathway.[11] Transforming growth factor β1 (TGF-β1) is an important factor in promoting collagen deposition in lung tissue and plays an important role in the process of PF, and quercetin can inhibit the TGF-β pathway lung to alleviate fibrosis,[12] in addition, quercetin can also affect the SphK1/S1P pathway and the Smad/β-catenin pathway,[13] and these pathways have an important regulatory role in the course of PF. The gene discussed is SPHK1; the disease is pemphigus foliaceus.