In a recent study, using RT-qPCR, two panels of transcripts related to the presence of CTCs (Panel 1: CK19, EpCAM, SCGB2A2 and Panel 2: EMP2, SLC6A8, HJURP, MAL2, PPIC and CCNE2), in two cohorts of breast cancer patients (metastatic and early), were evaluated. The gene discussed is CCNE2; the disease is breast cancer.