The MSRP IIRA supports highly rigorous, high-impact research projects that have the potential to make an important contribution to MS research, patient care, and/or quality of life. Research projects may focus on any phase of research, excluding clinical trials. The rationale for a research idea may be derived from laboratory discovery, clinical trial results, population-based studies, a clinicians firsthand knowledge of patients, or anecdotal data. Applications must include preliminary and/or published data that are relevant to MS and the proposed research project. For the Correlates of Disease Activity and Progression in MS Focus Area, applications must demonstrate access to the relevant specimens and/or data of the proposed cohort. Refer to Attachment 8: Letter(s) Confirming Access to Specimens and/or Data for more details. Note for projects involving animal models of MS: Applicants should be prudent in the choice of animal model(s) for their proposed research project. Applicants must justify the relevance of their proposed animal model(s) to the specific aspect of human MS to be studied. New Investigator option: The FY24 MSRP IIRA mechanism encourages applications from investigators in the early stages of their MS research career. The New Investigator option is designed to support the continued development of promising independent investigators that are early in their faculty appointments. Applications from Established Investigators and New Investigators will be peer and programmatically reviewed in separate groups. Principal Investigators (PIs) applying under the New Investigator option are encouraged to strengthen their applications through collaboration with investigators experienced in MS research and/or possess other relevant expertise as demonstrated by a record of funding and publications.