Moreover, transcription factor hypoxia-inducible factor 1-alpha (HIF1α) and the biological interaction between HER2 and CD44 may lead to upregulation of C-X-C chemokine receptor type 4 (CXCR4), which promotes tumor progression and NCRT resistance in gastroesophageal cancer [25, 26]. The gene discussed is CD44; the disease is neoplasm.