Gehrmann et al. (1995) showed that the level of APP expression is correlated with histopathological lesion development; therefore, APP is an important biomarker for the progression of MS. Also, Matías-Guiu et al. (2016) stated APP has a role in both demyelination and remyelination. Variants of FN1 are shown to be associated with MS in the study of Dardiotis et al. (2019). The gene discussed is APP; the disease is myeloid sarcoma.