These different binding properties of selumetinib compared to trametinib result in higher IC50 for selumetinib in MEK sensitive tumors (reported IC50 values of 50 nM for trametinib and 2.5 μM for selumetinib using the A549 bronchioloalveolar carcinoma cell monolayer cultures32) which is in agreement with work done by Gilmartin et al. 29 and Yamaguchi et al. 33. The gene discussed is MAP2K7; the disease is bronchioloalveolar carcinoma.