Allele frequencies for unique and shared mutations in four patients. Mutation allele frequencies for patients A) 308, B) 314, C) 317 and D) 319. A wide spread across frequencies is detected, with similar frequencies in stem cells and bulk tumor. Shared mutations are shown in beige, mutations unique to the cancer stem cells are shown in red whereas those unique to the bulk tumor are shown in blue. Plots for all patients in the study can be found in Additional file 1: Figure S5.