To be more specific, the results revealed that AQP9 expression were significantly correlated with gene markers, such as CD86 and CD115 for monocytes, CD68, IL10, CCL-2 for TAMs, IRF5, PTGS2 for M1 macrophages, CD163, MS4A4A and VSIG4 of M2 macrophages in breast, colon, lung and gastric cancers (P < 0.05; Fig. 5a–t). Here, AQP9 is linked to gastric cancer.