ENTPD1 and AL amyloidosis: ENTPD1, also known as CD39, is a cell membrane protein belonging to the ecto-nucleoside triphosphate diphosphohydrolase family and is highly expressed in various malignancies, such as lymphoma (Bastid et al., 2015), multiple myeloma (Häusler et al., 2011), and renal cell carcinoma (Yang et al., 2020).