In vitro, proliferation, invasion and angiogenesis of NSCLC cells are found to be promoted by nicotine via α7nAChR with activation of Signal transducer and activator of transcription1 (STAT1), E2F1, as well as induction of Src, PI3K, and Rb-Raf signaling pathways [85]. Here, E2F1 is linked to non-small cell lung carcinoma.