PDCD1 and neoplasm: To ascertain whether the diminished antitumor activity of αEGFR-mIL12mut2 stemmed from weaker tumor binding, we quantified the number of EGFR on MC38-EGFR5 tumor cells (Supplementary Fig. 5h), revealing a significantly higher count compared to PD-1 on intratumoral CD8+T cells (Supplementary Fig. 5f).