We conducted a comparative analysis of IRE1α KO cells and control THP-1 cells, focusing on several parameters: morphological features, lipopolysaccharide (LPS)-induced proinflammatory cytokine responses, specifically interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor (TNF) α measured by quantitative real-time PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA), as well as intracellular cholesterol accumulation and the expression levels of CD36 and ABCA1 genes following exposure to low-density lipoproteins (LDLs) derived from patients with atherosclerosis. Here, ERN1 is linked to atherosclerosis.