Single‐cell mRNA transcriptome analysis revealed that Il1f9 was primarily expressed in neutrophils, Il1f5 (encoding IL‐36Ra) was highly expressed in endothelial cells, neutrophils, and Lyz2+ mono‐macrophages/dendritic cells (mono‐φ/DCs), and Il1rl2 (encoding IL‐36R) was expressed in endothelial cells, epithelial tumor cells, and neutrophils in lung tumors from KL mice (Figure S2A–E, Supporting Information). Here, IL1RL2 is linked to neoplasm.