PIK3CB and pulmonary fibrosis: By blocking both the PI3K/AKT-HIF-1α and PI3K/PAK-RAF-ERK-HIF-1α pathways through the pyrrolo [1,2-a]azepine core, it inhibits SDF-1-mediated M2 macrophage polarization, thereby disrupting the positive feedback loop of fibrosis activation in pulmonary fibrosis