This may be explained by the role of Th cells in anti-tumor response in promoting immune response, including the expansion of B cells and cytotoxic T cells, to eliminate tumor cells by secreting cytokines such as TNF and IFNγ.32 However, the percentage of Th cells was slightly lower in OC patients with N3 tumors, which may occur because these tumors were highly metastatic and may have escaped the T cell-mediated immune response mechanism by the adaptation of primary tumor antigens.33 This evidence concerns the gene IFNG and neoplasm.