To further confirm if CCL2 or CCR2 influence cell mobility in migration and invasion without affecting tumor formation, silencing either CCL2 or CCR2 in two highly metastatic cell lines (S18 and 5-8F) was performed by RNA interference (RNAi) with two shRNAs targeting CCL2 (shRNA-CCL2-1 and shRNA-CCL2-2) or CCR2 (shRNA-CCR2-1 and shRNA-CCR2-2). This evidence concerns the gene CCR2 and neoplasm.