Antiserum raised against one of the phosphoresidue of MK5 (Ser354), one of the sites that we identified as being target of TLK1, has recently become commercially available, and we tested it to determine whether this specific MK5 phosphoprotein is present in several androgen‐dependent and androgen‐independent PCa cell lines (Fig. 3A and D). Here, TLK1 is linked to posterior cortical atrophy.