NFKB1 and B-cell chronic lymphocytic leukemia: Analogous to inactivation of IκBα, loss-of-function mutations of IκBε, which result for instance in the expression of truncated versions lacking the ankyrin repeats essential for the interaction with NF-κB dimers, have been reported in HL, CLL, and PMBL as well as at a lower frequency in DLBCL and MCL (Figure 5b) [205,206,207,208].