F2 and systemic lupus erythematosus: The presence of lupus anticoagulant was excluded based on the correctable APTT, that remained correctable even after 1 h incubation at 37 °C, on the corrigable prolongation of lupus anticoagulant sensitive APTT (APTT-LA), which was 136.7 s for the patient and it was 34.6 s in the 1:1 mixing study (APTT-LA of control plasma was 33.0 s) and on the negative result of diluted prothrombin time.