DLL3 and neoplasm: These analyses have identified four novel SCLC subtypes: NMF1, which is enriched in DNA damage repair and cell cycle pathways and may benefit from PARP inhibitors; NMF2, characterized by a high tumor mutational burden (TMB) and DLL3 expression, suggesting responsiveness to DLL3-targeted agents and immune checkpoint blockade; NMF3, which exhibits strong RTK signaling activity and may be susceptible to RTK inhibitors; and NMF4, which is linked to RNA metabolism and MYC pathway activation, indicating potential sensitivity to Aurora kinase inhibitors [36].