ERBB2 and neoplasm: Notably, HCT/130-mono-mIL12, with ~241-fold lower affinity for HER2 due to a ~105-fold faster dissociation rate from HER2 compared with that of HCT/0.5-mono-mIL12, induced the most robust tumor regression, resulting in a 79% (n = 11/14) rate of tumor-free survival in the mice, which was much higher than the rates of 57% (n = 8/14) for HCT/217-mono-mIL12, 29% (n = 4/14) for HCT/46-mono-mIL12, and 0% (n = 0/14) for HCT/0.5-mono-mIL12 (Supplementary Figure 4).