DRD2 and small cell lung carcinoma: The CRISPR/Cas9 method for creating immunocompetent genetically engineered mouse models of human SCLC has emerged as a straightforward, cost-effective, and easily adaptable approach to better understand how D2R agonist treatment affects immunoregulation within the tumour microenvironment as well as answer other questions focused on the role of immune system function in SCLC biology.