PLXNB1 and neoplasm: Expression levels of Plexin-B1 were moderate in Ptenfl/flp53fl/fl tumor cells (Supplementary Fig. S2L, antibody specificity shown in Supplementary Fig. S2M) and high in Ptenfl/flp53fl/flPLXNB1P1597L primary tumors and metastases (Supplementary Fig. S2N–S2P).