As mentioned, the pattern of NF-κB pathway mutations in PMBL is similar to that observed in cHL and largely different from the one characterizing ABC-DLBCL, in that activating mutations of upstream BCR pathway molecules (such as CD79 and CARD11) or TLR pathway components (MYD88) do not occur. This evidence concerns the gene NFKB1 and aneurysmal bone cyst.