Initial biological evaluation of (+)-discodermolide by the Longley group showed that it has immunosuppressive properties both in vitro and in vivo. The immunosuppression response was observed at a relatively low concentration that (+)-discodermolide was non-toxic in vitro. In both human peripheral blood leukocytes and murine splenocytes, (+)-discodermolide was found to suppress the two-way mixed lymphocyte reaction. In addition, mitogenic response of peripheral blood leukocytes was also suppressed by the (+)-discodermolide. Follow up experiments demonstrated that (+)-discodermolide also has anti-proliferative effects in several other non-lymphoid cell lines.