MAPK3 and melanoma: Interestingly, the combination of trametinib with the BRAFi PLX4720 induced ERK1/2 translocation to endoplasmic reticulum in BRAF mutant melanoma cells, and the protein kinase R-like endoplasmic reticulum kinase (PERK) phosphorylated ERK1/2 upon exiting endoplasmic reticulum [47].