Even though our work does not provide further mechanistic insight into the nature of the interaction between MELK and HDAC4, it is intriguing that MELK was identified as a bona fide interaction partner of HDAC4 in the BioGRID database (Boldt et al. 2016) and that HDAC6 inactivation becomes increasingly toxic with overexpression of MELK in cancer cell lines in the CCLE database (Figure 4F). This evidence concerns the gene HDAC4 and cancer.