To further establish the relevance of these findings to human biology, we measured DNMT3A levels in circulating HSPCs from the blood of cancer-free, healthy younger and older donors (Fig. 5H) and of patients with NSCLC, from whom we documented increasing frequencies of HSPCs with age and worsening stage (Fig. 5I). This evidence concerns the gene DNMT3A and non-small cell lung carcinoma.