GJA1 and neoplasm: To evaluate this hypothesis, we analyzed BALB/ByJ mice for tumor development, tumor incidence, bronchoalveolar lavage fluid inflammatory infiltrates, pro-inflammatory genes, KC protein content, immunostaining, and two additional markers for hallmarks of early-stage LUAD: a gap junction gene (Gja1) and epiregulin (Ereg; an epidermal growth factor receptor (EGFR) ligand).