CLK4, or Cdc2‐like kinase 4, is a dual‐specificity kinase belonging to the LAMMER kinase family.[5, 8] CLK4 regulates the AS of pre‐mRNA by phosphorylating serine‐ and arginine‐rich splicing proteins within the spliceosome.[13, 14] Therefore, the aberrant AS in several cancers can be moderated by inhibiting CLK4 activity. Here, CLK4 is linked to cancer.