We further measured the ex-vivo response of the samples to ibrutinib in a co-culture model of stromal cells and CLL cells, which suggested that the New-PG responded less to the BcR inhibitor ibrutinib (Supplementary Fig. 5c, Ibrutinib: 40 nM, Wilcoxon signed-rank test p = 0.01). Here, BCR is linked to B-cell chronic lymphocytic leukemia.