Our previous studies showed that ERK kinase‐mediated phosphorylation of XPO5 at proline‐directed serine/threonine sites, coupled with the peptidyl‐prolyl isomerase Pin1‐catalyzed conformation change, impaired the nuclear export of pre‐miRNAs and downregulated miRNA expression during HCC development,15, 16, 17, 18 highlighting the important role of phosphorylation in determining XPO5 function. This evidence concerns the gene PIN1 and hepatocellular carcinoma.