In addition to the 10 genes, we also considered 5 clinical variables, which are known to characterize breast tumors with the PAM50 status: estrogen receptor (ER) [87], progesterone receptor (PER) [87], human epidermal growth factor receptor (HER) [88], lymph node status [89], and tumor staging code [90]. The gene discussed is PER1; the disease is breast neoplasm.