SPI1 and plasma cell myeloma: We found that circSPI1s were mainly expressed in hematopoietic malignancies, e.g., acute myeloid leukemia (AML), chronic myeloid leukemia (CML), acute lymphocytic leukemia (ALL), chronic lymphocytic leukemia (CLL), myeloproliferative neoplasm (MPN), and multiple myeloma (MM), suggesting the hematopoietic lineage-specific pattern (Fig. 1B), similar to the lineage specificity observed for the parental SPI1 gene.