RB1 and small cell lung carcinoma: SCLC is characterized by frequent alterations in key molecular pathways, including the dysregulation of the MYC family of oncogenes [125,126,127], the inactivation of tumor suppressors such as TP53 and retinoblastoma (RB)1 [127,128,129], and the aberrant signaling of the Notch, Hedgehog, and PI3K/AKT/mTOR pathways [130,131,132,133].