ERBB2 and triple-negative breast carcinoma: Interestingly, both normal and carcinoma cells from low-grade (luminal A, luminal B, and HER2-negative) tumors with better prognosis tended to express more circRNA than high-grade triple-negative breast carcinoma (TNBC) cells, indicating the less accumulation of circRNAs in TNBC cells with faster progression rate.