TGFB1 and cancer: Given that our previous studies have shown that TGF-β1/TGFβR axis is involved in immunosuppression by GC [3, 31], and that galunisertib is undergoing clinical trials in human cancers [32–34], it is possible that galunisertib may be a promising immunotherapeutic agent for the attenuation of TGF-β1-dependent immunosuppression in human GC.