Gene encoding for thymic stromal lymphopoietin (TLSP), a central mediator of eosinophilic inflammation, is located on a pseudo-autosomal region of the X and Y chromosomes (Xp22.3 and Yp 11.3). A single nucleotide polymorphism of this region predisposes male patients to develop EoE (4). Here, KLK11 is linked to eosinophilic esophagitis.