In the current study, we used the CIBERSORT algorithm to determine the proportion of infiltrating immune cells and found higher infiltration of CD8+ T cells and M1 type macrophages in the ovarian serous cystadenocarcinoma tissues in TCGA data in the high CCL18 expression group compared with their corresponding low‐expression groups. Here, CCL18 is linked to ovarian serous cystadenocarcinoma.