In addition, TGFβ1 induces primary esophageal smooth muscle cell contraction, a mechanism dependent on the canonical Smad2/3 pathway and phospholamban, a sarcoendoplasmic reticulum protein that regulates calcium flux, which is upregulated in EoE biopsies (79, 85). Here, TGFB1 is linked to eosinophilic esophagitis.