By analyzing circRNA expression in training (4 MM patients and 4 healthy controls) and validating set (60 MM patients and 30 healthy controls), Zhou et al. (Zhou et al., 2020) identified that circ-PTK2 and circ-RNF217 were upregulated and correlated with poor treatment response and survival, while circ-AFF2 was downregulated and associated with good treatment response and survival in MM patients, which might make them potential prognostic biomarkers in MM. Here, AFF2 is linked to Miyoshi myopathy.