IL4 and neoplasm: As described in Section 3 of this paper, the Gas6/AXL pathway regulates the immune microenvironment by modulating important components of the immune microenvironment, including the tumor’s vascular system; critical biomarkers such as MHC-I molecules and PD-L1; important cytokines such as IL-4, CCL3-5 and G-CSF; and key immune cells such as phagocytes, DCs, NK cells, effector T cells and Tregs.