CD8A and non-small cell lung carcinoma: In concordance with the suppressed CD8+ T cell activity, we found that MTSS1 knockdown resulted in obvious upregulation of PD-L1 protein expression in H1975 cells (Fig. 2d), which was further confirmed in additional human non-small-cell lung cancer cell lines H358, H1299 and bronchial epithelium cell lines 16HBE, BEAS-2B (Fig. 2d).