Consistent with the in vivo data, activin A induced monocyte/macrophage migration in vitro and upregulated the expression of adhesion molecules and chemokine receptors on monocyte‐derived peritoneal macrophages, including Cx3cr1, which was shown to mediate recruitment of macrophages into several types of tumors (Held‐Feindt et al, 2010; Schmall et al, 2015) and to increase macrophage survival during tumor metastasis (Zheng et al, 2013). This evidence concerns the gene CX3CR1 and neoplasm.