RNF213 and multiminicore myopathy: Surprisingly, after RNF213 silencing, circZXDC was remarkably expressed in the VSMCs but not in the ECs or HEK293T cells (Figure 2A), which suggested that VSMC RNF213 knock-down mimics a similar observation in RNF213 4810kMUT patients and possibly implies that VSMCs might be the major contributor to circZXDC up-regulation in MMD.