BCR and amyloidosis: In particular, in 6 out of 18 ALκ, 10 out of 29 ATTR, 13 out of 19 AA, and 1 out of 4 rare ALys and Aβ2M amyloidosis cases, a weak and irregularly distributed unspecific reactivity for anti-ALλ antisera was observed (Figs 1 and 2).