CCL21 and breast cancer: Moreover, the proposed molecular mechanism responsible for the regulation of VEGF-C was analyzed in MCF-7 mock and MCF-7-CCL21-knocked in (KI) breast cancer cells and the efficacy of nucleotransfection is presented in Figure 1H and I. Quantitative PCR, Western blot, and ELISA confirmed that CCL21/CCR7 pair has the ability to regulate the expression of the lymphangiogenic factor VEGF-C in the analyzed MCF-7 breast cancer cells (Figure 1H - L).