It has been shown that TNFα induces ER stress/UPR activation in murine fibrosarcoma L929 cells, human osteoblast-like SaOs-2 cells, synovial fibroblasts from patients with rheumatoid arthritis, and human airway smooth muscle cells (Xue et al., 2005; Connor et al., 2012; Yap et al., 2020b; Hameister et al., 2020). Here, TNF is linked to rheumatoid arthritis.