Table 2. Samples with A20 deletions and/or the absence of A20 by immunohistochemistry.

Sample No.	Diagnosis	A20 deletion	A20 expression	EBER1 (ISH)	LMP-1	EBNA-2
1	PAL	Homozygous loss	−	+	+	+
2	PAL	LOH	−	+	+	+
3	PAL	LOH	+/−	+	+	+
4	PAL	LOH	+/−	+	+	+
5	NKTL	Homozygous loss	u.d.	+	−	−
6	NKTL	LOH	u.d.	+	−	−
7	NKTL	LOH	+/−	+	−	−
8	DLBCL-e	LOH	+	+	+	−
9	MTX-LPD	normal	−	+	+	−

Abbreviations: PAL, pyothorax-associated lymphoma; NKTL, NK/T cell lymphoma, nasal type; DLBCL-e, EBV positive diffuse large B-cell lymphoma of the elderly; MTX-LPD, methotrexate-related lymphoproliferative disorders; LOH, loss of heterozygosity; EBER1, Epstein-Barr virus encoded RNA1; LMP-1, latent membrane protein-1; EBNA-2, EBV nuclear antigen-2; +, positive (50% or more); p+, intermediate expression (less than 50%); −, negative (0%); +/−, equivocal positive; u.d., undetermined.