Although the BRAFi-resistant melanoma with impaired PTEN also has the ability of resistance to MEKi, their IC50s are less than 1.2 μM [Sk-mel28(IC50 = 0.015 μM)/Sk-mel28R (IC50 = 0.14 μM), RI = 9.3; WLH2615 (IC50 = 0.56 μM)/WLH6215R(IC50 = 1.2 μM), RI = 2.1]. Here, PTEN is linked to melanoma.