These “private” CTC mutations affected significantly mutated genes in melanoma (BRAF, NRAS, MAP2K1, KIT) or were in genes associated with a more aggressive phenotype like CTNNB1. Thus, ctDNA and CTC analyses of blood from melanoma patients can reveal mutations not found by bulk analysis of randomly selected primary tumor tissue of the same patient. This evidence concerns the gene MAP2K1 and neoplasm.