PLD4 and malignant colon neoplasm: Gao et al. reported that phospholipase D4 (PLD4) were involved in the activation process of M1 phenotype macrophages and developed antitumor effects in colon cancer cells [49], while another study demonstrated that ruyiping extract (RYP) reduced lung metastasis in triple-negative breast cancer by regulating macrophage polarization through reducing signaling transducer and activator of transcription (STAT) 6 [50].