Antiapoptotic protein signature in CLL lymph nodes. Protein lysates obtained from peripheral blood (PB, n = 5) and lymph node (LN, n = 6) were probed for phosphorylated-ERK, total ERK, Bim, and actin as indicated. The expression of these proteins in ex vivo LN was similar to changes observed upon in vitro stimulation of PB CLL cells with CD40.