Morse CB, et al. - In a cohort of ovarian carcinoma (OC) patients, the link between homologous recombination (HR) deficiency (HRD) and the presence of tumor infiltrating lymphocytes (TILs) was examined, as well as the relative impact of these on overall survival. They prospectively enrolled patients who had carcinoma of the ovary, fallopian tube, or peritoneum. On specimens collected at primary surgery, CD3+ T cells and CD68+ tumor associated macrophages (TAMs) were analyzed using immunohistochemistry. The definition of HRD was a damaging mutation in one of 12 genes in the HRR pathway or promoter hypermethylation in BRCA1 or RAD51C. HRD OC was identified in 98 of 250 patients overall analyzed. HRD OC were enriched for CD3+ TILs and CD68+ TAMs. The overall survival was improved the most in patients that had both CD3+ TILs and HRD OC vs non-HRD OC with low CD3+ TILs.