PRNP and multiple sclerosis: It should be noted that a decrease in PrPc has also been observed in a transgenic mouse model (Dupuis et al., 2002) and human cases of amyotrophic lateral sclerosis (Kovacs et al., 2002) and is also evoked in multiple sclerosis (Scalabrino, 2022), suggesting that these two other spinal cord diseases might probably share common neurodegenerative mechanisms and the decrease in PrPc, involved in several neurodegenerative disorders, could be a key element.