IGF1R and small cell lung carcinoma: Features of SCLC tumors are a reflection of alterations in genes associated with the disease including overexpression, somatic mutation and amplification, resulting in a plethora of targeted therapies existing or in development including FAK inhibitors, RTK inhibitors targeting KIT, IGF-1R, EPHB4, RON and MET as well as their downstream pathways including the PI3K/AKT/mTOR and MYC [108].