Next, we applied the optimized pSILAC workflow to study how the immunopeptidomes of two melanoma cell lines with overactive MAPK pathway, Ma-Mel-63a (BRAF V600E) and UKE-Mel-105b (homozygous NRAS Q61R), are modulated by pharmacological inhibition of the MAPK pathway. Here, NRAS is linked to melanoma.