The observations of less than 5% VAF of the IDH1 mutation in cases 3, 5, and 6 in a contexts of 51%‐70%, 31%‐50%, and 41%‐60% estimated tumor cellularity and 33%, 13%, and 18% VAF of the coexisting EGFR, KRAS, or PIK3CA mutation suggest presence of IDH1 mutation in a tumor subpopulation. The gene discussed is KRAS; the disease is neoplasm.