MAPK3 and adenocarcinoma: For example, in a recent in vitro study in human immortalized lung epithelial cells and adenocarcinoma cells, Liu et al. (2011) reported that As-induced ROS generation activated protein kinase AKT and the extracellular signal-regulated kinase (ERK1/2) leading to increased downstream expression of vascular endothelial growth factor (VEGF), an important angiogenesis regulator.