CD44 and neoplasm: Our study aims to prove that AA can recruit more CD11b+CD44+PD-L1+ cells, and even if its function is not good, it can still turn cold tumors into hot tumors, and then use PD1 monoclonal antibody to further enhance immune cells after increasing the expression of PD-L1.Elevated PD-L1 interacts with PD1 on CD8+ T cells, resulting in a reduced immune anti-tumor killing effect and PD-L1 expression can be an important marker for the effectiveness of immunotherapy [35, 36].