Possibly, the true prognostic value of SCUBE2 is not observed in tissue biopsies because BCSCs are rare cells compared with differentiated cells with lower expression of SCUBE2. TNBC has a higher proportion of BCSCs compared with other BrCa subtypes (Honeth et al., 2008), promoting progression through proliferation, migration to metastatic sites, and therapy resistance. The gene discussed is SCUBE2; the disease is invasive breast carcinoma.