Despite the variability in definitions of DLL3 positivity and the tumor heterogeneity among the 30 identified studies, most patients with SCLC were found to be DLL3-positive.

This SLR demonstrates that DLL3 is expressed in most patients with SCLC and presents a potentially impactful therapeutic target.

Future investigations should explore the impact of DLL3 expression using large populations with validated tests for DLL3 expression to better understand the dynamics of DLL3 as a therapeutic target for SCLC.