SRSF1 and neoplasm: The overexpression of Clk2 kinase was also shown to sustain cell growth in breast cancer, while its silencing was demonstrated to reduce the SRSF1 phosphorylation and to induce the production of the ENAH isoform, which is typical of the mesenchymal phenotype and associated with tumor invasion and metastasis (Yoshida et al., 2015).