IFNL1 and cancer: To elucidate the induction of type III IFN relative to type I IFN in cancer cells in the context of PBMC co-cultures, we isolated the cancer cells after treatment of the co-cultures with HER2 ADC or Control ADC and then conducted qPCR analysis of IFNL1 and IFNB. IFNL1 and IFNB were upregulated in cancer cells at comparable levels in response to HER2-ADC but not to Control ADC (Fig. 5a, Supplementary Fig. 16a).