Introduction:Recent studies have shown that deeper free light chain responses are associated with improved outcomes in patients with systemic light chain (AL) amyloidosis, yet the optimal long-term goal remains unclear.(N Engl J Med 2018; 378:518-528) Unlike multiple myeloma, where the role of minimal residual disease (MRD) testing is well established, in AL amyloidosis the methods to best identify MRD, and whether achieving MRD would benefit disease outcomes, warrant further investigation. (Blood Cancer J. 2021 Jun 21;11(6):117; PLoS ONE 15(7): e0235713. https://doi.org/10.1371/journal.pone. 0235713) In AL amyloidosis, the toxic misfolded oligomers and amyloid deposits are both due to clonal immunoglobulin light chains and cause organ damage and death. Hence, the tracking of clonotypic light chain sequences could present a promising approach for detecting the maintenance of profound therapeutic responses. Our study aimed to assess the frequency with which next generation sequencing (NGS) detects light-chain clones consistent with the patient's clonal light-chain isotype and to determine whether the light-chain sequences identified were encoded by light-chain variable region genes considered AL-related.(Journal of Clinical Oncology 2019 37:15_suppl, 8010; Blood (2017) 129 (3): 299-306; PLoS One 2022 Feb 25;17(2):e0264407)