Activation of XBP1-s by unsaturated aldehyde 4-hydroxy-trans-2-nonenal (4-HNE), a byproduct of lipid peroxidation, promotes the production of triglyceride and aberrant lipid accumulation in DCs, and subsequently, causes the failure of DCs to assist T cells in exerting their anti-tumor function [123]. The gene discussed is XBP1; the disease is neoplasm.