After orthotopically implanting 10,000 tumor cells into the fourth mammary fat pads of NSG mice to ensure tumor growth of both L2G-labeled WT (pool control clonalities) and PLXNB2 KO MDA-MB-231 cells (pooled KO cells), we assessed spontaneous metastasis of these tumors to the lungs (Fig. 2a). This evidence concerns the gene PLXNB2 and neoplasm.