As EphA4 is a cognate receptor of RNase1 via a direct ligand-receptor binding 24, we next determined, in addition to its expression on tumor cells, whether EphA4 was also expressed on immune cells in the TME, where it may interact with secretory RNase1 and be involved in RNase1-mediated antitumor function. This evidence concerns the gene RNASE1 and neoplasm.