NRAS and melanoma: BRAF, NRAS and TERT mutations are present in more than 66% of melanomas; a study performed in 2020 measuring ctDNA levels harboring these mutations in 19 different patients with late-stage melanoma concluded that detectable levels of ctDNA had a shorter PFS and shorter median time for disease progression at 50 days compared to 146 days for patients that did not have detectable ctDNA (Figure 2A) (Marczynski et al., 2020).