TP53 and cancer: Adding phosphate groups to serine, tyrosine, or threonine to control enzyme activity and cell signaling (e.g., p53 phosphorylation) is associated with cancer.[74] Glycosylation mutations in the V4 region of HIV envelope protein mediate immune escape partially by affecting antibody binding to the virus.[75] Ubiquitination modification can regulate the occurrence and development of tumors, neurodegenerative diseases, autoimmune diseases, and other diseases through multiple pathways.