To gain initial clues, we compared cellular MAP4K4 levels to the activation status of MAPK/ERK1/2, MEK1/2, MAKP/JNK1/2, MAPK/p38 as well as the serine/threonine protein kinase AKT in lung adenocarcinoma cell lines, evaluated by immunoblotting using specific antibodies against phosphorylated ERK, MEK, JNK, p38, or AKT. This evidence concerns the gene MAPK3 and lung adenocarcinoma.