MAPK3 and pancreatic adenocarcinoma: It was reported that an increase in the activation of Erk1/2 might lead to an up-regulation in the levels of a cyclin-dependent kinase (CDK) inhibitor, p21Waf1/Cip1, in human pancreatic adenocarcinoma cell lines [32], which is consistent with our findings that p21Waf1/Cip1 is up-regulated in this cell after co-culture with γδ T cells.