MTOR and non-small cell lung carcinoma: Furthermore, it is noteworthy that the relationship between EGFR mutations and PD-L1 expression remains largely controversial, since pre-clinical data reported that the activation of EGFR signaling directly drives “intrinsic” PD-L1 up-regulation in a NSCLC model through several pathways such as PI3K/AKT/mTOR, Ras/RAF/MEK/ERK, JAK/STAT, and NF-kB (39).