AKT1 and non-small cell lung carcinoma: However, research found that PD-L1 expression was associated with the STAT3, AKT, and ERK pathways in wild-type EGFR NSCLC, and ubiquitin ligases Cbl-b and c-Cbl could downregulate PD-L1 expression by inhibiting phosphorylation of STAT3/AKT/ERK pathways (63).