Small-cell lung cancer (SCLC) involves loss of function mutations in two major tumor suppressor genes – p53 and Rb1. This leads to the G1S cell cycle checkpoint no longer functioning correctly, and cell cycle regulation falling to the G2M checkpoint only. WEE1 is master regulator of G2M checkpoint and preclinical research has suggested that it could be a good therapeutic target for SCLC. Triparna Sen, PhD, Memorial Sloan Kettering Cancer Center, New York, NY, explains a recent preclinical study in which SCLC cell-lines in tumor-bearing mice were treated with either immunotherapy plus WEE1 inhibition or immunotherapy alone. The study found a significant decrease in tumor volume shortly after treatment started with the combination therapy, including some individuals having complete tumor regression. This is promising preclinical evidence to support the further investigation of WEE1 inhibition in the treatment of SCLC. This interview was conducted at the virtual European Society for Medical Oncology Targeted Anti-Cancer Therapies (ESMO TAT) Congress 2022.