Using ultrasensitive single molecule array technology, serum levels of NfL, GFAP, and tau were measured before and every 3 weeks in 10 women receiving adjuvant EC (epirubicin 90 mg/m2 and cyclophosphamide 600 mg/m2) every 3 weeks × 3, followed by weekly paclitaxel 80 mg/m2 × 9–12 weeks after surgery due to early breast cancer. The gene discussed is NEFL; the disease is breast carcinoma.