A. Prostate cancer cells are treated with CCL2 (30 ng/ml) for 24 h, and western blot for CCR2 is performed. B. Prostate cancer cells are treated with CCL2, CCL17, and CCL22 (30 ng/ml) for 24 h, and western blot for CCR4 is performed. C. Prostate cancer cells are co-cultured with U937 or U937-M cells for 24 h, and western blot for CCR4 is performed. D. Prostate cancer cells are placed in transwell inserts and treated with CCL17 and CCL22 (0–30 ng/ml). After 24-h incubation, PC-3 and DU145 cells that had migrated through the membrane are stained. The mean optical density (OD) value is read using a microreader at 595 nm. Migration of LNCaP cells is assessed with a wound-healing assay. Adjustments of brightness, contrast, and size are applied to the whole images of western blot-based analyses without elimination of any information present in the original, including backgrounds. Data are presented as mean ± SD. All experiments are performed in triplicate, and mean values are shown. *p < 0.05, **p < 0.01, ***p < 0.001.