To further explore the potential role of IRE1α/XBP‐1s signalling in KDELR2 overexpression in rats with COPD, we next investigated the influence of IRE1α/XBP‐1s signalling on KDELR2 via pharmacological disruption of the IRE1α/XBP‐1s signalling cascade (Figure 5A). Here, ERN1 is linked to chronic obstructive pulmonary disease.