However, another study found that CCL5 expression in OvCa cancer stem cells recruited Tregs to promote immunoresistance and tumor metastasis via intercellular CCL5-CCR5 interactions, and co-culture with ovarian cancer cell lines induced the expression of MMP9 in Tregs, which promoted the invasion and metastasis of OvCa cells (87). Here, CCL5 is linked to ovarian cancer.