2.4. MTT assay

To assess the viability, 1 × 10⁴ cells in 96‐well flat‐bottom plates were treated with increasing concentrations of Trametinib or TRAIL as indicated for 72 hours. To each well, 20 μL of 5 mg/mL MTT reagent (Roche, Basel, Switzerland) was added, and the plates were incubated for 1 hour in the tissue culture incubator at 37°C. The crystals of formazan were solubilized with 150 μL DMSO after the media were removed. The absorbance at 450 nm was determined by microplate reader.