Our data resonate with the observations that by the age 70 years, at least 5% of people have known leukemia mutations in a subset of circulating hematopoietic cells.20 This includes mutations in the same genes, such as in DNMT3A, TET2, and BCOR, which we identified in tumor-infiltrating leukocytes in our study. The gene discussed is BCOR; the disease is leukemia.