The bone marrow microenvironment is vitally important to the oncogenic growth of MM cells; further studies have been performed to explore the impact of circular RNAs on the MM microenvironment.12 We first predicted the presence of a secreted circBUB1B circular RNA fragment (1804 bp) containing 13 exons using circbase database (Fig. 4a), which contained a putative internal ribosome entry site (IRES) sequence and might encode a novel BUB1B isoform with 544 amino acids (Fig. 4b), termed as “circBUB1B_544aa” in the present study. The gene discussed is BUB1B; the disease is Miyoshi myopathy.