PDCD1 and neoplasm: In this regard, prior studies demonstrated that PD-L1+ Keap1f/f/Ptenf/f (K1P) NSCLC tumor-bearing mice have elevated tumoral PD-L1 expression and increased presence of PD-1+ CD8+ T-lymphocytes compared to uninfected K1P or KrasG12D/p53f/f tumor-bearing mice [18].