APOA2 and myeloid sarcoma: Receiver operating characteristic analysis identified total apolipoprotein-A2 (Apo-A2; area under the curve [AUC] = 0.808), HDL-3-Apo-A2 (AUC = 0.806), HDL-Apo-A2 (AUC = 0.798), VLDL-2-phospholipids (PLs; AUC = 0.774), VLDL-3-PLs (AUC = 0.769), and VLDL-3-triglycerides (AUC = 0.770) as robust biomarkers for distinguishing NMOSD from HCs, whereas VLDL-3-PLs (AUC = 0.791) and HDL-3-Apo-A2 (AUC = 0.752) effectively differentiated NMOSD from MS.