Previous research has shown that aberrantly high expression of CCL17 in various cancers, including leukemia, lung cancer, bladder cancer, breast cancer, gastric cancer, and liver cancer (Bouchet et al. 2020; Gao et al. 2020; Higuchi et al. 2019; Lim et al. 2014; Mishalian et al. 2014; Wang et al. 2018, 2019; Ye et al. 2022), serves as a primary driver for recruiting CCR4-expressing Tregs into the TME. The gene discussed is CCR4; the disease is cancer.