The aim of this study was to apply TLA on samples collected from MCL and FL patients enrolled in prospective clinical trials of the Fondazione Italiana Linfomi (FIL) and lacking a PCR‐detectable BCL1 (MTC) or BCL2 (MBR and MCR) rearrangement, in order to assess the feasibility of TLA as marker screening approach. Here, BCL2 is linked to mantle cell lymphoma.