If feasible, all DLBCL cases need to be tested for MYC expression andfurther testing for MYC and BCL2/BCL6 rearrangements in case of MYCexpression> 40% and BCL2 > 50% (strong and cytoplasmic).Fluorescent in situ hybridization (FISH) break-apart probes are used,and FISH testing is recommended for all DEL with germinal center-bphenotype and high Ki67 baseline CNS involvement and extensive extranodal disease (IB)10:90% agreement (two suggestions not to do testing for HGBCL and BL). The gene discussed is MKI67; the disease is diffuse large B-cell lymphoma.