Meanwhile, hucMSCs also increased the CSA of muscle fibres, especially fast muscle fibres, elevated the percentage of slow in fast muscle fibres and the number of muscle fibres (Figures2E and S3F), and suppressed obesity‐associated upregulation of Atrogin1 and MuRF1 protein levels (Figure2F). This evidence concerns the gene TRIM63 and obesity due to melanocortin 4 receptor deficiency.