However, tumor by secrete IL‐10 (Interleukin 10), VEGF (Vascular endothelial growth factor), and so on inhibiting factor prompted the myeloid cells abnormal differentiation, APC‐related precursor DC (Dendritic cells) decrease, at the same time, peripheral immature DC due to no expression or low expression costimulatory molecules, CD80 and CD86 cannot be activated, thus, the number of normal mature DCs in peripheral blood decreases, while the number of immature DCs increases. This evidence concerns the gene IL10 and neoplasm.