Investigation of heterogeneity in the association between interferon beta and disability progression in multiple sclerosis: an observational study. Shirani A, Zhao Y, Karim ME, Petkau J, Gustafson P, Evans C, Kingwell E, van der Kop M, Oger J, Tremlett H Eur J Neurol. 2013 Dec 18. PMID: 24351059. Abstract CommentRecommendBookmarkWatch