MKI67 and neoplasm: The growth of tumors was monitored via MRI (Figure 6A), we found that circPIK3C2A-KD significantly reduced tumor growth and invasion, and FOXM1-OE effectively abolished the inhibitory effect of circPIK3C2A-KD as shown in hematoxylin-eosin (HE) and immunohistochemical (IHC) staining (Ki67+ for proliferating cells, cleaved caspase 3+ (CC3+) for apoptotic cells) results (Figures 6A, D).