The main aim of our study was to determine whether SLFN11 transcript and protein could be accurately and reproducibly measured in 2 different cohorts of serous ovarian cancer, one internal and another from The Cancer Genome Atlas (TCGA), considering the following aspects: (a) the sensitivity of HGSOC to DDAs, (b) the need for clinically useful prognostic biomarkers for CT treatments, (c) the potential connection between SLFN11 and TILs, and (d) the potential of developing SLFN11 as a biomarker in the clinic, based on results in preclinical models. The gene discussed is SLFN11; the disease is ovarian serous adenocarcinoma.