Assuming that the link between Sororin abundance and ERK phosphorylation is conserved in lung adenocarcinomas, these findings suggested that the knockdown of IWS1 and its replacement by the phosphorylation-site mutant IWS1S720A/T721A in NCI-H522 and NCI-H1299 cells would also result in inhibition of ERK phosphorylation. Here, IWS1 is linked to lung adenocarcinoma.