IL22 and hepatocellular carcinoma: Lejeune et al. (2002) reported that, for downstream phosphorylation signals, that is, mitogen activated protein kinase (MAPK) signaling pathways, IL-22 was found to use tyrosine kinase (Tyk-2) and c-Jun N-terminal kinase (Jak-1) in H4IIE rat hepatoma cell line [45].