PLCG1 is involved in the coculture model. (A) PLCG1 expression in KG1a cells without stroma contact (KG1a) and after coculture with HS5 cells for 7 to 24 hours. (B) Western blotting of phospho-PLCG1 in KG1a cells before and after coculture with HS5 stroma treated with CD11b antibody for various time intervals (top). (Bottom) The fold-increase in apoptosis in KG1a cells treated under different conditions is shown. The anti-CD11b antibody (AB) used was P4H9. (C) Early apoptosis in KG1a cells cultured alone (KG1a only), unmodified KG1a cocultured with HS5 (KG1a from coculture), and KG1a pretreated with herbimycin (see “Methods”) before HS5 coculture. Error bars indicate SEM.