However, over a short period of 4-6 h without compromised cell viability and with minimal influence by cell proliferation/growth, both siPB2 and siPB2−10 comparably reduced the size of tumor clusters of all five tested models, including human MDA-MB-231, MDA-MB-468, SKBR3, and HS578T cells, and mouse 4T1 cells (Fig. 3d–g, and Supplementary Fig. S5a-n), suggesting that PLXNB2 is required for tumor cell clustering in breast cancers. Here, PLXNB2 is linked to breast cancer.