A, Baseline (preinfusion) plasma NfL levels divided by immune effector cell–associated neurotoxicity syndrome (ICANS) grade. B, Receiver operating characteristic (ROC) classification of patients who develop any grade ICANS (≥1) vs no ICANS (grade 0) for baseline NfL level and available postinfusion day 1 markers. C, Univariate correlation between pretreatment factors and available preinfusion biomarkers. D, Blood plasma NfL levels relative to timing of lymphodepletion and chimeric antigen receptor (CAR) T-cell infusion; group comparisons here were between any grade ICANS (≥1) vs no ICANS (grade 0). Multiple comparison validation per false discovery rate. CNS indicates central nervous system; CRP, C-reactive protein; HD, high-dose; Hx, history; IT, intrathecal; LDH, lactate dehydrogenase; Neuro, neurologic disease; MTX, methotrexate; RT, radiotherapy.