NFKB1 and aneurysmal bone cyst: A significant proportion of the C1 cluster consisted of ABC tumors [51] and was enriched with BCL6 structural variants and frequent mutations affecting the NF-κB pathway and FAS (fatty acyl synthase); TP53 mutations and loss of CDKN2A and RB1 occurred in the C2 cluster; the C3 cluster showed BCL2 mutations and frequent mutations of KMT2D, CREBBP, and EZH2; and C4 showed mutations in four linker genes and four core histone genes.