The A20 (also called TNFAIP3)/PRDM1/SHGC-79576 DNA-FISH Probe is designed to detect deletion of the A20 gene located on 6q23 and the PRDM1 gene located on 6q21 relative to the control locus SHGC-79576 on 6p12, using fluorescence in situ hybridization (FISH). Deletion of 6q is observed in all types of B-cell malignancies, where two commonly deleted regions map to the A20 and PRDM1 gene region. Loss of the A20 gene has been observed in ~20% of non-Hodgkin lymphoma (NHL) cases, ~20% of mucosa-associated lymphoid tissue (MALT) lymphoma casesand in nonsplenic marginal zone lymphomas (MZLs) cases.The loss of the A20 gene has been observed most frequently in mantle cell lymphoma (MCL) and diffuse large B-cell lymphoma (DLBCL) cases with a frequency rate of 31% and 38%, respectively. In DLBCL, inactivation of is seen more frequently in the activated B-cell (ABC) subtype of (50%) versus the germinal center B-cell (GCB) subtype (22%). DLBCL cases exhibit a variety of complex 6q deletions, which encompasse either A20 or PRDM1 alone or together as part of a larger deletion. Additionally, the deletion of the PRDM1 gene has been observed in 53% of primary central nervous system lymphomas (PCNSLs).