ERBB2 and neoplasm: To extensively profile circRNAs across breast cancer tumorigenesis, a total of 26 primary and metastasis tumor scRNA-seq samples from 20 breast invasive carcinoma (BRCA) patients with different luminal stages including 19 TNBC, 3 HER2 negative, 2 luminal A, and 2 luminal B samples were investigated49–51.