PDCD1LG2 and neoplasm: As shown in Fig. 5A and B, the 2 patients with lung adenocarcinoma had different expressions of PD-L2, high PD-L2 expression resulted in higher tumor uptake of [68Ga]Ga-HN11-1 in patient 1 (IHC score 80%, SUVmax: 4.1, Fig. 5A) compared to patient 2, who had low PD-L2 expression (IHC score 15%, SUVmax: 2.1, Fig. 5B), while the SUVmax of [18F]F-FDG was 15.5 for patient 1 and 25.9 for patient 2.