Circulating tumor DNA from the KRYSTAL-1 and CodeBreaK 100 trials has been demonstrated to be able to identify multiple acquired pathological genomic alterations among patients treated with KRAS G12C inhibitors, with or without anti-EGFR, in up to 70% of the patients, but particularly among patients treated with the combination [51,52]. The gene discussed is KRAS; the disease is neoplasm.