Neural precursor cell expressed developmentally downregulated 4-like (NEDD4L), an E3 ubiquitin ligase critical to the ubiquitination process, plays key roles in the regulation of cancer stem cells, as well as tumor cell functions, including cell proliferation, apoptosis, cell cycle regulation, migration, invasion, epithelial–mesenchymal transition (EMT), and tumor drug resistance, by controlling subsequent protein degradation through ubiquitination. The gene discussed is NEDD4L; the disease is cancer.