pNfH and NfL levels dosed at baseline in the CFS of SMA type 3 patients were comparable to those observed in controls (n = 9, age: 29.0 [22.0‐54.5] year‐old) and were far below the average values described in patients affected by either SMA type 1 (6.874 ng/mL and >10 000 pg/mL, respectively) or amyotrophic lateral sclerosis (5.270 ng/mL and 2961 pg/mL11) (Figure 2A and 2). Here, NEFL is linked to myalgic encephalomeyelitis/chronic fatigue syndrome.