GZMB and neoplasm: It has been described that TGF-β1 inhibits the expression of cytolytic gene products in CD8+ T cells.[36] Accordingly, in our study sGARP reduces the production of the cytolytic protein granzyme B and diminishes the proliferation of CD8+ T cells, suggesting that sGARP is an important antagonist to cytotoxic T cell function in the tumor microenvironment.