For instance, while fractional abundance of ATM, NRAS and IGF1R mutations in the primary tumour was 35%, 20% and 2%, respectively, the prevalence of these mutations in the corresponding plasma samples was 0.05, 0.07 and 0.07% (Fig. 4c), whereas in the sputum, mutations fractions were 0.04, 0.03 and 0.03% (Fig. 4d). The gene discussed is NRAS; the disease is neoplasm.