To compare the cytotoxic potential of [(HER2)2xCD16] tribody with that of trastuzumab, we initially analyzed freshly isolated PBL from different PDAC patients (n = 9) and HDs (n = 6) that had been co-cultured with HER2-expressing PDAC cells (PancTu-I- or Panc89 cells) or breast cancer cells (MCF-7 cells) in the RTCA system (Figure 4A). Here, ERBB2 is linked to breast cancer.