ABL1 and leukemia: To elucidate the mechanism of TSPAN32 suppression in BCR-ABL transduced leukemias, the intracellular signaling transduction of TSPAN32 was investigated using a protein-protein interaction (PPI) network.25 To identify TSPAN32 binding partners, we overexpressed HA-TSPAN32 in 293 T cells, then performed immunoprecipitation with HA antibody for a peptide mass spectrometry (MS) assay (Fig. 7a).