EGFR and Barrett esophagus: The presented study aimed to (1) analyze the two functional single-nucleotide polymorphisms (SNPs) in the EGF and EGFR genes and their gene-gene interactions in relation to the development of BE and EAC, (2) analyze EGF and EGFR mRNA expressions in the esophageal tissue samples with and without endoscopically visible pathological changes in GERD patients, and (3) compare EGF plasma levels in patients with GERD to those found in healthy controls from the Central European population.