Ibrutinib presents a breakthrough in CLL treatment, but cases of resistance which cannot be explained by genetic alterations are emerging (Ahn et al., 2017; Kaur and Swami, 2017; Landau et al., 2017), and recent studies indicate that alternative pro‐proliferative signalling pathways, mainly NF‐κB, were only partially blocked by this small molecule (Dadashian et al., 2019; Jayappa et al., 2017). Here, NFKB1 is linked to B-cell chronic lymphocytic leukemia.