IL17F and hemorrhagic stroke: Interleukin‐17A and its receptor IL‐17R play a significant role in inflammation and BBB breakdown after stroke.17 IL‐17 is predominantly produced by various immune cells such as natural Th17 cells, γδT cells, T‐helper cells, and innate lymphoid cells.18 After hemorrhagic stroke, there is an increased level of IL‐17A, one of six subtypes of the IL‐17 family (IL‐17A to IL‐17F) within the CNS.19 IL‐17 receptor (IL‐17R) has five subtypes which include IL‐17RA to IL‐17RE, where IL‐17A and IL‐17F can bind to IL‐17RA.