Israel Technion researchers have found that the ubiquitin enzyme RNF4 binds to oncogenic proteins to give cancer cells longer lives. Increased levels of RNF4 have been found in colon and breast cancer patients. Removing or inhibiting RNF4 leads to the death of cancer cells.
http://www.technion.ac.il/en/2016/12/crucial-enzyme-for-tumor-development/