CD4 and neoplasm: AXL also appears to promote tumour immune evasion by downregulating DC, NK, and CD4+/CD8+ T-cells, decreasing major histocompatibility complex class I molecules, favouring immunosuppressive chemokines/cytokines, promoting myeloid-derived suppressor cell expansion, M1 to pro-tumour M2 macrophage polarisation, T-cell exclusion, activating regulatory T-reg cells, and increasing PD-L1 expression on tumour cells [2,7,8,9,10].