TP53 mutations reshape the tumor immune microenvironment and set the terms for checkpoint blockade. TP53 mutation immunotherapy response is therefore context dependent: in lung adenocarcinoma the mutation marks a hotter tumor and predicts longer progression-free survival on anti-PD-1 therapy, while in TP53-mutant myeloid leukemia a cold, suppressed niche blunts that benefit. One gene, opposite outcomes. Why TP53 status rewires the tumor immune microenvironment TP53 sits on chromosome 17p13.1 and is the most frequently altered gene across human cancers, mutated in more than 50 percent of malignancies and in over 70 percent of esophageal squamous cell carcinoma, small cell lung cancer, squamous lung cancer, and complex-karyotype acute myeloid leukemia. For decades…