CCL21 and Familial prostate cancer: In another study by Maolake et al., the authors divulged that by activating Chemokine (C-C motif) ligand 21/C-C chemokine receptor 7 (CCL21/CCR7) axis, Tumor necrosis factor-α (TNF-α) contributed to PCa lymph node metastasis using DU145, PC3, LNCaP-SF, and LNCaP prostate cancer cell lines [140].