MiR‐129 was reported previously to be regulated by lncRNAs.27, 28 In this study, we for the first time demonstrated a direct link between PCAT‐1 and miR‐129 in MM and that the PCAT‐1 level in MM‐derived PCs was significantly higher than that in the control and negatively associated with the level of serum miR‐129. Here, PCAT1 is linked to Miyoshi myopathy.