A method of classifying a subject diagnosed with multiple sclerosis as being more likely to have benign multiple sclerosis or as being more likely to have typical relapsing remitting multiple sclerosis (RRMS), the method comprising determining a level of expression of at least one gene involved in the RNA polymerase I pathway selected from the group consisting of RRN3, POLR1D and LRPPRC in blood cells of the subject, wherein said determining is effected using an RNA and/or a protein detection method and comparing said level of expression of said at least one gene in said blood cells of said subject to a reference expression data of said at least one gene obtained from blood cells of at least one subject pre-diagnosed as having BMS and/or from blood cells of at least one subject pre-diagnosed as having typical RRMS, wherein BMS is characterized by Expanded Disability Status Scale (EDSS) of less than 3.0 following at least 10 years from onset and/or diagnosis of multiple sclerosis, and wherein said typical RRMS is characterized by an EDSS higher than 3.0 within less than 10 years of disease onset and/or diagnosis, (i) wherein a decrease above a predetermined threshold in said level of expression of said at least one gene in said blood cells of the subject relative to said reference expression data of said at least one gene obtained from said at least one subject having said typical RRMS classifies the subject as being more likely to have the BMS, and/or; (ii) wherein an increase above a predetermined threshold in said level of expression of said at least one gene in said blood cells of the subject relative to said reference expression data of said at least one gene obtained from said at least one subject having said BMS classifies the subject as being more likely to have the typical RRMS, and/or; (iii) wherein when a level of expression of said at least one gene in said blood cells of the subject is identical or changed below a predetermined threshold as compared to said reference expression data of said at least one gene obtained from said at least one subject having said BMS, then the subject is classified as being more likely to have the BMS, and/or; (iv) wherein when a level of expression of said at least one gene in said blood cells of the subject is identical or changed below a predetermined threshold as compared to said reference expression data of said at least one gene obtained from said at least one subject having said typical RRMS, then the subject is classified as being more likely to have the typical RRMS; thereby classifying the subject as being more likely to have BMS or as being more likely to have typical RRMS. (i) wherein a decrease above a predetermined threshold in said level of expression of said at least one gene in said blood cells of the subject relative to said reference expression data of said at least one gene obtained from said at least one subject having said typical RRMS classifies the subject as being more likely to have the BMS, and/or; (ii) wherein an increase above a predetermined threshold in said level of expression of said at least one gene in said blood cells of the subject relative to said reference expression data of said at least one gene obtained from said at least one subject having said BMS classifies the subject as being more likely to have the typical RRMS, and/or; (iii) wherein when a level of expression of said at least one gene in said blood cells of the subject is identical or changed below a predetermined threshold as compared to said reference expression data of said at least one gene obtained from said at least one subject having said BMS, then the subject is classified as being more likely to have the BMS, and/or; (iv) wherein when a level of expression of said at least one gene in said blood cells of the subject is identical or changed below a predetermined threshold as compared to said reference expression data of said at least one gene obtained from said at least one subject having said typical RRMS, then the subject is classified as being more likely to have the typical RRMS; thereby classifying the subject as being more likely to have BMS or as being more likely to have typical RRMS.