For example, during the course of combined ICI therapy, both CNAs and the TERT promoter C250T mutation present at baseline in ctDNA of patient P4 were no longer detected in follow-up samples, whereas in patient P6, both CNAs and one tumor-specific mutation (KMT2D-p.Q2337*) undetectable at baseline became recognizable at disease progression (KMT2D VAF: 1%; TFx estimate: 4.6%), and increased massively before the patient’s death (KMT2D VAF: 9.8%; TFx, estimate: 12.7%; Supplementary Fig. 17). The gene discussed is TERT; the disease is neoplasm.