In line with these observations, in breast cancer cells knockdown of Ly6E/K, the human homologue of the stem cell antigen-1 (sca-1), reduces both TGF-β induced-SMAD1/2 phosphorylation and surface expression of PD-L1 while increases binding of cancer cells to NK cells [66]. This evidence concerns the gene TGFB1 and breast carcinoma.