KRAS and non-small cell lung carcinoma: When analyzing all treated Stage IV NSCLC patients with known PD-L1 status (n = 261) stratified on KRAS mutational status and PD-L1 expression levels (negative, low or high) (Figure 4A), we observed that increased PD-L1 expression correlated with significantly better OS in KRASMUT patients (p = 0.036, Figure 4B).