All nine clones (three clones for each of the Fab‐format BAR‐bodies A, B, and C) of the recombinantly expressed Fab‐format Ars2 BAR‐bodies were tested for their binding capacity to the DLBCL cell lines U2932 (BCR with Ars2‐reactivity) and HBL‐1 (BCR with no Ars2‐reactivity) by flow cytometry (Figure 3). Here, BCR is linked to diffuse large B-cell lymphoma.