Johnson et al. found high CCN1 gene expression in multiple myeloma (MM) associated BM stromal cells, but no CCN1 expression in cultured (normal or malignant) plasma cells (Johnson et al. 2014), whereas Dotterweich et al. did demonstrated CCN1 mRNA and protein in the cells of their MM cell line, which could be markedly increased by MSC contact or addition of recombinant CCN1 (Dotterweich et al. 2014). Here, CCN1 is linked to AL amyloidosis.