Furthermore, we observed differences between the ERCC1-XPF complex and median PFS in LS-SCLC, although statistical significance was not reached (univariate: positive expression 10.8 [95% CI 4.09–17.55] months versus negative expression 13.3 [95% CI 7.32–19.31] months; p = 0.06). Here, ERCC4 is linked to small cell lung carcinoma.