The first study to use this approach involved applying SNS to study the evolution of aneuploidy in patients with triple-negative (ER-/PR-/HER2-) breast cancers (TNBCs; negative for, respectively, the estrogen receptor, progesterone receptor and the receptor tyrosine-protein kinase erbB-2 (HER2)) [34]. The gene discussed is PGR; the disease is breast cancer.