Using duodenal ligation to simulate occult reflux and microaspiration, it can be found that the GERD combined with BLM-induced PF animal model has the same increased expression of extracellular-regulated kinases (ERK) and TGF-β1/Smad compared with the classical BLM animal model (Li, M., et al., 2021). Here, TGFB1 is linked to gastroesophageal reflux disease.