Although C3 is similar to a Claudin-low subtype in some aspects, such as incidence (approximately 10%) [37] and cancer stem cell-like features, these subtypes differ from one another in the following aspects: (1) hormone receptor status—C3 is dominant in luminal A subtypes, whereas triple-negative (TN) tumors account for more than half of CL tumors [17]; and (2) prognosis - CL behaves more poorly than the luminal subtype but better than the basal-like subtype from METABRIC datasets (Fig. S8); C3 has worse prognosis even compared with the basal-like dominant C2. Here, NR4A1 is linked to cancer.