CD4 and neoplasm: Previous studies have also shown that immature pDCs recruited to the tumor site mediated by the interaction of CXC chemokine receptor 4 (CXCR4), resulting in promotion of pDCs-mediated generation of CD4+CD25+Foxp3+Treg cells, which leads to anergy and immune suppression, favoring the immune escape of tumor cells (75, 76).