IL17A and systemic lupus erythematosus: Additionally, other studies have reported that levels of IFN‐γ are elevated during thrombosis,[37] and Th1 and Th17 cells are increased in patients with SLE,[38] or chronic immune thrombocytopenia.[39] These studies are consistent with our observation that the patients in Cluster 2 are mostly female thrombotic APS, with the highest incidence of secondary APS and thrombocytopenia and the highest number of IFN‐γ producing Th1 cells and IL‐17 producing Th17 cells.