Bisindolylmaleimide VIII acetate (Ro 31-7549 acetate) is a potent and selective protein kinase C (PKC) inhibitor with an IC50 of 158 nM for rat brain PKC. Bisindolylmaleimide VIII acetate has IC50s of 53, 195, 163, 213, and 175 nM for PKC-α, PKC-βI, PKC-βII, PKC-γ, PKC-ε, respectively. Bisindolylmaleimide VIII acetate facilitates Fas-mediated apoptosis and inhibits T cell-mediated autoimmune diseases.