JUN and neoplasm: Sze et al. (2013) observed that HBxΔ24 can increase the invasion and metastasis abilities of tumor cells by enhancing C-Jun transcriptional activity and increasing the transcription of matrix metalloproteinases. Zhang et al. (2008) observed that HBxΔ27 can activate the arachidonic acid-catalyzing enzyme 5-LOX osteopontin and eventually promotes the migration of liver cancer cells. Taken together, these findings support those of his study showing that MC-LR and ctHBx synergistically promote the migration and invasion of HepG2 cells in vitro.