Furthermore, our own studies have recently shown that repression of microRNA200, and the upregulation of ZEB1 and BMP4 associated with epithelial to mesenchymal transition (EMT) program also render increased expression of PD-L1 on lung cancer cells in mice and humans8, 9 Thus, PD-L1expression is regulated by both tumor intrinsic and tumor extrinsic pathways. This evidence concerns the gene BMP4 and neoplasm.