FOS and muscle atrophy: In summary, we identified miR‐29b‐3p as a muscle atrophy‐associated exosomal miRNA with potential to be uptake by neuronal cells which consequently inhibits neuronal cell differentiation via targeting the mRNAs of c‐FOS, BCL‐2, RIT1, LAMC1, and upregulation of lncRNA HIF1α‐AS2.