CD4 and cancer: The cross-presentation mechanism causes CD4+ Th cells to simulate Tc lymphocytes in eradicating tumor cells (26,27).The production of cytokines IL-1, IL-6, Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF), and Granulocyte-Colony-Stimulating Factor (G-CSF), which induce thrombopoiesis as well as megakaryopoiesis, cause thrombocytosis in cancer patients.