A monoclonal antibody raised against the N-terminus of the SEL1L protein [34] was used to screen a panel of whole lysates from five human cell lines, including MCF7 and SKBr3 (breast cancer), KMS11 (Ig-K-secreting multiple myeloma), 293FT (embryo kidney) and the non-tumorigenic epithelial breast cell line MCF10A. This evidence concerns the gene SEL1L and AL amyloidosis.