ILP-1 (Δ2BIR) and ILP-2 interact with processed caspase 9 in cells. 293 cells were transfected with expression vectors encoding GST, GST–ILP-1, GST–ILP-2, and/or caspase 9 as indicated (2 μg/well) (A), GST–ILP-2, caspase 9, and/or caspase 9 mutants as indi- cated (B), and GST–ILP-1, GST–ILP-1 (Δ2BIR), GST–ILP-2, and/or caspase 9 as indicated (C). Cell lysates were coprecipitated with glutathione-Sepharose beads, washed, resolved by SDS-PAGE, transferred to nitrocellulose membranes, and immunoblotted with an anti-caspase 9 antibody (Pharmingen). The full-length (Pro) and processed (p35/37) forms of caspase 9 are indicated. Cell lysates were also examined by immunoblot analysis to confirm transfection efficiency and loading (input). The bands marked with asterisks are found only when the GST–ILP-1 vector is coexpressed with caspase 9 and presumably represent the caspase 9-induced cleavage products which have been reported previously (, ). Molecular masses (in kilodaltons) are shown.