Interleukin‐17 is associated with expression of programmed cell death 1 ligand 1 in ovarian carcinoma

The programmed cell death 1/programmed cell death 1 ligand 1 pathway was successfully targeted in cancer immunotherapy. Elevated interleukin‐17 (IL‐17), which is known in autoimmune diseases, has recently been recognized in cancer patients. We investigated the role of IL‐17 in the regulation of expression of programmed cell death 1 ligand 1 in ovarian cancer by evaluating changes in the number of IL‐17‐producing cluster of differentiation 4 helper T cells (Th17) and γδT cells (γδT17) in PBMC of 52 gynecological cancer patients (including 30 ovarian cancer patients) and 18 healthy controls. The occupancy ratio of Th17 and γδT17 was higher in ovarian cancer and endometrial cancer patients than in controls, determined by multi‐color flow cytometry (Th17: P