Accordingly, tumor cells were extracted for subpopulation analysis, and the identified malignant cells clustered into eleven subclones: BRCA_SRGN, BRCA_SLC39A6, BRCA_ITGB3, BRCA_PECAM1, BRCA_PPP1R1B, BRCA_VCAM1, BRCA_ICAM1, BRCA_S100A9, BRCA_GLUL, BRCA_TASTD2 and BRCA_AGR3 (Fig. 3A, Additional file 1: Figure S4). Here, S100A9 is linked to neoplasm.