Although typically expressed on vascular endothelial cells, VEGFR2 is aberrantly expressed in many tumors, including multiple myeloma.50, 51, 52 Prior reports have suggested an interaction of Sdc1 with VEGFR2 in myeloma-induced angiogenesis and vascular mimicry in melanoma;53, 54, 55 our work shows that this interaction is direct. Here, KDR is linked to AL amyloidosis.