(I) Bim(EL)/Bcl-xL were cotransfected into HeLa cells with empty vector (IP negative control) or Beclin 1-Flag; Bim(EL)-EE/Bcl-xL were also cotransfected into HeLa cells with Beclin 1-Flag. Anti-Flag (M2) was used for immunoprecipitation. Data are shown as mean ± SD. NS, not significant. 