STAT3 and non-small cell lung carcinoma: RAS‐dependent mitogen‐activated protein kinase/extracellular signal‐regulated kinase (MAPK/ERK‐1/2) signaling, phosphatidylinositol 3‐kinase (PI3K)–protein kinase B (Akt)‐mediated cell proliferation and EGFR‐regulated ERK, and signal transducer and activator of transcription 3 (STAT3) pathways are the key regulating networks of NSCLC.54, 55, 56, 57