APOA1 and transient ischemic attack: In future studies, serum APOA1-UP levels can be measured by MRM coupled with stable isotope dilution (SID) mass spectrometry for absolute quantitation to improve the sensitivity, and the diagnostic potential of total APOA1-UP should be evaluated in patients with other cerebrovascular diseases, such as hemorrhagic stroke, transient ischemic attack (TIA), and cerebral venous thrombosis.