The NCCN guidelines recommend FISH testing for chromosomal abnormalities including t(14;18), t(8;14), and t(3;v) prior to treatment for individuals with a primary diagnosis of diffuse large B-cell lymphoma DLBCL and disease progression.

MYC gene breaks and BCL2 gene breaks or BCL6 gene breaks can be used for the diagnosis of double-hit lymphoma (DHL).

Abnormal amplification of MYC, BCL2, and BCL6 gene copy number may also be one of the important factors affecting the prognosis of DLBCL.National data published by Li Jianyong et al. in Jiangsu Provincial People's Hospital in 2015 showed that, among 180 patients with high expression of MYC IHC (more than 40%), there were 22 cases of MYC breaks (12%), and 13 cases of MYC copy number increase (7%, of which 10 cases were obtained cases, and 3 cases of amplification) (3-4 signaling sites were gain, and >4 were amplification). 282 patients with high BCL2 IHC expression (50% or more) had 22 cases (7%) of BCL2 breaks and 56 cases (20%, of which 38 cases were gain, and 18 cases of amplification) of BCL2 copy number gain. 282 patients with high BCL2 IHC expression (50% or more) had 22 cases (12%) of MYC breaks and 13 cases (7%, of which 38 cases were gain, and 18 cases of amplification) of MYC copy number gain. 282 patients with high BCL2 IHC expression (50% or or more) patients had 22 BCL2 breaks (7%) and 56 BCL2 copy number increases (20%, of which 38 were acquired and 18 were amplified). The authors concluded that patients with MYC or increased BCL2 copy number had a poor prognosis and required a more aggressive treatment program.