A total of 55 cases (16%), 20 FP and 35 FN, including (D)LBCL (n = 28, 51%), MCL (n = 5, 9%), and IBCL (n = 22, 40%), demonstrated discordant results between p53 IHC and TP53 mutational analysis, as indicated in online resource 2. The gene discussed is TP53; the disease is mantle cell lymphoma.