Furthermore, overexpression of PD-L1 significantly decreases the activities of PI3K/AKT and RAS/MEK/ERK pathways, leading to the suppression of lung cancer cell growth in vitro and in xenografts (Wang X. et al., 2020), providing evidence for the tumor suppressive role of PD-L1 in specific tumor type. This evidence concerns the gene MAP2K7 and lung carcinoma.