Similar to the findings in the liver, markedly elevated levels of ER stress markers, including BiP, phosphorylated IRE1α (p-IRE1α), and the activated form of XBP1 (XBP1s), along with the increased SGLT1 signals, were observed in the lungs, intestine, and pancreas of the CF rabbits without sotagliflozin treatment (Supplemental Figures 9–11). Here, XBP1 is linked to cystic fibrosis.