TGFB1 and neoplasm: Previous experimental studies have fostered optimism, suggesting that blocking TGF-β may even render immune-excluded tumors responsive to ICIs.48 However, our RNA-seq data reveal that the preexisting immune infiltration remains a major determinant of the anti-PD-L1/TGF-β response.49–51 Baseline primary tumor samples of responders showed enrichment of immune-related signatures, and increased densities of TLS.