The proportion of FSCN1+ tumor cells in peripheral blood samples (median, 90.9%; interquartile range [IQR], 85.4%–100.0%) was significantly higher than in tissue samples (median, 6.09%; IQR, 1.10%–18.25%) (Supplementary Fig. 1A [available online]). The gene discussed is FSCN1; the disease is neoplasm.