In addition to alarmins, recent work (2021–2023) has highlighted a growing pipeline of non-invasive biomarkers for pediatric GERD—including salivary pepsin, exhaled breath metabolites (volatile sulfur compounds, acetic acid), serum inflammatory mediators (e.g., TNF-α), and oral microbiome signatures—although most candidates still lack pediatric validation and standardization. This evidence concerns the gene TNF and gastroesophageal reflux disease.