In this study, we used an SCLC chemoresistant cell line orthotopic xenograft model and observed that the TGF-β signalling inhibitor LY2157299 (galunisertib), which was bioavailable, effectively suppressed the TGF-β signalling pathway, augmenting tumour chemotherapy responsiveness in combination with chemotherapeutic drugs. Here, TGFB1 is linked to small cell lung carcinoma.