KRAS and lung adenocarcinoma: Given that IWS1 phosphorylation also promotes the activation of ERK via the Sororin/p-ERK positive feedback loop, we asked whether IWS1 phosphorylation influences ERK phosphorylation in lung adenocarcinoma cell lines, harboring KRAS (A549 and NCI-H460) or EGFR (NCI-H1975, PC-9, and NCI-H1650) mutations.