PLP1 and amyotrophic lateral sclerosis: The decrease in MBP was associated with a reduction in the contents of other major myelin proteins, including CNP and PLP, in FTD patients carrying a progranulin (but not C9orf72 repeat expansion) mutation, as well as in ALS patients carrying a TARDBP mutation (Kang et al., 2013; Marian et al., 2023).