TGFB1 and pulmonary fibrosis: Wang further found that microcystin-leucine arginine (LR) can reduce TGF-β/Smad signaling, regulate macrophage polarization, block EMT and myofibroblast differentiation, and bind to GRP78 to inhibit the UPR signaling pathway, which contributes to alleviating pulmonary fibrosis [45].