The relative sensitivity of the SUM159 cells to the CSPG4-targeted 212Pb-RIC compared to the control 212Pb-RIC in these studies is consistent with previous results using other breast cancer cell lines and α-particle RICs [15,21], thus indicating mAb 225.28 is a suitable carrier for targeted RIT of this TNBC tumor model. Here, CSPG4 is linked to neoplasm.