The treatment of ropivacaine repressed the cell growth of MDA-MB-231 cells in vivo, while miR-27b-3p inhibitor could reverse this effect, as shown by tumor size (Figure 6A), tumor volume (Figure 6B), tumor weight (Figure 6C), and the levels of ki-67 and PCNA (Figure 6D). The gene discussed is PCNA; the disease is neoplasm.