In vivo, priming is decreased in BM-derived CLL cells compared with PB-derived CLL cells. BM-derived CLL cells (n = 6) were found to be significantly less primed than their PB (n = 6) counterparts using BIM BH3 peptide at 0.01μM (P = .011), with means depicted as horizontal bars ± SEM and P ≤ .05 as indicated by asterisks. LN-derived (n = 4) CLL cells trended toward having increased priming compared with their BM-derived counterparts (P = .11).