Cyclosporin B is a cyclic peptide immunosuppressant primarily studied in research for its role in preventing organ transplant rejection by modulating T-cell activity. It shows potential in treating autoimmune diseases such as psoriasis and rheumatoid arthritis through suppression of specific immune responses. Additionally, it has been investigated for neuroprotective effects, potentially reducing neuronal damage in ischemic stroke and neurodegenerative disorders. In multidrug resistance studies, Cyclosporin B enhances the efficacy of anticancer drugs by inhibiting efflux pumps in tumor cells.