The radioactivity distribution of 99mTc‐HYNIC‐αLAG‐3 predominantly encompassed blood, liver, spleen, lung, and kidney, with no notable variance among LAG‐3+ A549, LAG‐3− A549, and blocked LAG‐3+ A549 mice (non‐tumor tissues: p > 0.05, Figure S5a, Supporting Information). This evidence concerns the gene LAG3 and neoplasm.