LECT2 makes the amyloid list

In this issue of Blood, Mereuta et al report that we must now add leukocyte cell–derived chemotaxin 2 (LECT2) to the list of proteins that can cause systemic amyloidosis, a fibrillar protein deposition disease that leads to end-organ damage and related symptoms and requires a tissue diagnosis demonstrating apple-green birefringence in Congo Red–stained sections viewed microscopically under polarized light. When dissected from affected tissue, digested into protein fragments of different lengths for proteomic analysis, and assessed by mass spectrometry for their original constituents, amyloid deposits reveal a unique signature of chaperones such as apolipoprotein E and serum amyloid P-component (arrows) as well as the identity of the critical main culprit: the amyloid-forming protein (red boxes).