CASP3 and pulmonary fibrosis: Dormant D2.0R breast cancer cells cultured on BME + COL1 were treated with AZD0530 (SFK inhibitor) and AZD6244 (MEK1/2 inhibitor). Apoptosis and viability were assessed by caspase-3/7 assays, Annexin V/PI staining, and MTS assays, while pERK1/2 levels were confirmed by immunoblotting. In vivo efficacy was validated in lung fibrosis mouse models via tail-vein injection and metastatic burden analysis.