Modern genomic technologies have revolutionized eosinophilia evaluation, with whole exome sequencing (WES) uncovering pathogenic STAT6 mutations in pediatric allergic cases [45, 46] and next-generation sequencing (NGS) identifying disease-associated STAT1 variants in familial eosinophilic esophagitis (EoE) [47]. The gene discussed is STAT1; the disease is eosinophilic esophagitis.