Inhibitor of interaction between calcineurin and its substrate nuclear factor of activated T cells (NFAT); blocks at the substrate recognition site but not at the catalytic site (Kd = 0.8 mM). Inhibits NFAT dephosphorylation and nuclear import. Also prevents induction of cytokine mRNAs that are downstream targets of NFAT. Purity 98%. MW (observed): 284.31