SCLC is well-known to release growth factors, such as bombesin, gastrin-related peptide (GRP), HGF, VEGF, TGF-β, HGF, and FGF, which have been shown to activate focal adhesion pathways in several cancers [117,118,119,120,121,122,123,124,125]. Here, HGF is linked to small cell lung carcinoma.