To determine whether the pathway activated by IWS1 phosphorylation and leading to Sororin expression and ERK phosphorylation is active in human lung adenocarcinomas (LUAD), we examined the expression and phosphorylation of IWS1, the alternative splicing of U2AF2, and the abundance of ERK and phosphor-ERK, CDK1, and phosphor-CDK1 and cyclin B1 in a set of 40 human LUAD samples. The gene discussed is CDK1; the disease is lung adenocarcinoma.