In ST-ZFTA ependymomas, constitutive activation of NF-κB signaling by the ZFTA-RELA fusion may contribute to diffuse cytoplasmic EMA expression, potentially amplified by hypoxia- and necrosis-associated stress responses, providing a mechanistic link between the molecular driver and the observed immunophenotype. The gene discussed is NFKB1; the disease is ependymoma.