MKNK1 and cancer: Based on our previous studies demonstrating the ubiquitin-proteasomal degradation of MNK1/2 induced by VNLG-152R in breast (9, 18) and prostate (33, 34) cancer cell lines and the role of SYVN1 as an E3 ligase involved in ubiquitination and proteasomal degradation of several proteins (35–42), we hypothesized that SYVN1 might play a key role in the ubiquitination and subsequent degradation of MNK1/2.