Dose-dependent WFA-induced apoptotic cell death in renal carcinoma kidney cell lines and induction of ER (endoplasmic reticulum) stress markers such as phosphorylation of eIF-2α (eukaryotic initiation factor-2α), XBP1 (X-box binding protein 1) splicing, upregulation of glucose-regulated protein (GRP)-78 and CHOP (CAAT/enhancer-binding protein-homologous protein). This evidence concerns the gene XBP1 and renal carcinoma.