PTK2 and Miyoshi myopathy: This was in line with our previous study that circ-PTK2 was correlated with higher MM risk (7), and the reason could be that (1): Circ-PTK2 might act as sponge to miRNAs, which subsequently inhibited the functional regulation of these miRNAs towards cell activity, thereby circ-PTK2 promoted cell proliferation, migration and inhibited cell apoptosis of MM cells.