Fine-needle aspiration with a 16-gauge needle is preferred to a 22-gauge needle because the latter may not yield adequate tissue to evaluate for some types of amyloid, such as ATTR, for which connective tissue is needed.7 If renal biopsy is contraindicated or cannot be obtained, evidence of AL in a fat pad, lip, or bone marrow biopsy and presence of proteinuria >500 mg/d is sufficient for diagnosis.8, –10. The gene discussed is TTR; the disease is amyloidosis.