In vivo models studying olaparib in BRCA1-deficient ovarian cancer observed significantly increased proportions of CD4+ and CD8+ effector T-cells infiltrating intratumorally and peripherally and, notably, an increase in intra-tumoral CD4/Foxp3+ Tregs was not seen (Ding et al., 2018). This evidence concerns the gene CD4 and ovarian carcinoma.