Steady-state levels of components of the NF-κB pathway in MM cells. (A) Steady-state levels of NF-κB subunits in nuclear-enriched protein fraction from MMCLs. Nuclear extracts were prepared, and expression of the proteins indicated at right was analyzed on immunoblots: known and unknown (?). NF-κB mutations for MMCLs with high NF-κB index are indicated in parentheses. (B) Immunoblot for CYLD in MMCLs.