ctDNA kinetics were evaluated in another work driven by Herbreteau et al., in which plasmatic ctDNA BRAF or NRAS mutations were quantified by ddPCR at baseline and after 2–4 weeks of treatment in an exploratory cohort (n = 53) and a validation cohort (n = 49) of metastatic BRAF or NRAS-mutant melanoma treated with anti-PD-1 alone or in combination with anti-CTLA-4 [100]. Here, CTLA4 is linked to melanoma.