This review article from Neurology Neuroimmunology & Neuroinflammation, centers on the growing significance of neurofilament light chain (NfL) assays in managing multiple sclerosis (MS). It explains how NfL levels in blood can indicate neuroaxonal damage, offering a less invasive method than traditional MRI for predicting disease progression and monitoring treatment effectiveness in MS patients. While highlighting the potential of NfL as a prognostic and monitoring biomarker, the article also addresses current challenges in its widespread clinical application, such as the need for standardized measurements and established reference ranges, as well as the influence of confounding factors like age and other health conditions. The authors ultimately suggest that NfL, especially when combined with other biomarkers, holds promise for personalizing MS treatment and improving patient outcomes.