TTR and amyloidosis: It can be classified into several subtypes based on the accumulated fibrils, with over 95% of cases being amyloid light chain cardiac amyloidosis (AL-CA), resulting from monoclonal plasma cell-derived immunoglobulin deposition and amyloid transthyretin cardiac amyloidosis (ATTR-CA), resulting from liver-derived plasma protein deposition with further divided into wild-type ATTR-CA (ATTRwt-CA) and variant/hereditary ATTR-CA (ATTRv-CA) amyloidosis [2, 3].