UBC and neoplasm: Encoding and decoding ubiquitin codes are responsible for all levels of epigenetic changes, and by changing substrate protein activities, they can also activate and repress effects on gene transcription depending on their target proteins and the ubiquitin chain types, all of which are connectively related to the process of tumor proliferation (Kim and Baek, 2006; Zheng et al., 2008; Fradet-Turcotte et al., 2013; Yeh et al., 2018).