The phosphorylation of protein kinase B, also known as AKT (p-AKT at both threonine 308 and serine 473 for PI3K pathway), ERK1/2 (p-ERK1/2 for ERK pathway) and p38 (p-p38 for p38 pathway) measured with Western blot was increased in the eosinophils isolated from EA compared with those from healthy or non-eosinophilic controls (Fig. 5A). Here, MAPK3 is linked to Esophageal atresia.